Safety alarm method, device and system for primary air system of coal mill and storage medium

Abstract

The invention discloses a safety alarm method, device and system for a primary air system of a coal mill and a storage medium. The safety alarm method, device and system are used for giving an alarm for abnormity of the primary air system of the coal mill. The method comprises the steps that the abnormal types of a primary air system causing spontaneous combustion of pulverized coal of a coal mill are obtained, wherein the abnormal types at least comprise air temperature abnormity, temperature rise rate abnormity, valve failure and valve jamming; determining a corresponding preset parameter according to the exception type; whether the primary air system is abnormal or not is judged according to the parameter values of the preset parameters; and when the primary air system is abnormal, alarm information indicating that the coal powder of the coal mill has the spontaneous combustion risk is sent out. According to the scheme, various abnormal conditions are identified, the situation that adaptability is poor and misinformation is prone to occurring due to a single parameter is avoided, and the accuracy of safety early warning of the coal mill is improved.

Description

Technical Field

[0001] The present application relates to the field of safety control technology, and in particular to a safety alarm method, device, system and storage medium for a primary air system of a coal mill. Background Art

[0002] The primary air at the inlet of a medium-speed coal mill is a mixture of hot and cold primary air. If the primary air system deviates from normal operation, it can cause spontaneous combustion or explosion within the mill. Current methods for controlling and monitoring coal mill operation either rely on a single parameter, which has poor adaptability and is prone to false alarms, or rely on manual testing, which is subject to data lag and human error.

[0003] Therefore, how to provide a safety alarm method for the primary air system of the coal mill to improve the accuracy of the coal mill safety warning has become a technical problem that needs to be solved urgently. Summary of the Invention

[0004] The present application provides a coal mill primary air system safety alarm method, device, system and storage medium to improve the accuracy of coal mill safety warning.

[0005] The present application provides a coal mill primary air system safety alarm method, comprising:

[0006] Obtaining the primary air system abnormality type that causes coal powder spontaneous combustion in the coal mill, wherein the abnormality type at least includes abnormal air temperature, abnormal temperature rise rate, valve failure, and valve jamming;

[0007] Determine corresponding preset parameters according to the abnormality type;

[0008] Determining whether the primary air system is abnormal according to the parameter value of the preset parameter;

[0009] When an abnormality occurs in the primary air system, an alarm message is issued indicating that there is a risk of spontaneous combustion of coal powder in the pulverizer.

[0010] In one embodiment, when the abnormality type is wind temperature abnormality, determining the corresponding preset parameters according to the abnormality type includes:

[0011] According to the preset corresponding relationship table, the preset parameter corresponding to the abnormal wind temperature is determined to be the volatile matter content of the pulverized coal;

[0012] The determining whether the primary air system is abnormal according to the parameter value of the preset parameter includes:

[0013] determining the primary air explosion temperature of the coal mill according to the volatile matter content of the coal powder;

[0014] Comparing the primary air inlet temperature of the coal mill with the primary air explosion temperature of the coal mill;

[0015] Determine whether the primary air system is abnormal based on the comparison results.

[0016] In one embodiment, when the abnormality type is a temperature rise rate abnormality, determining the corresponding preset parameter according to the abnormality type includes:

[0017] According to the preset corresponding relationship table, the preset parameter corresponding to the abnormal temperature rise rate is determined to be the volatile matter content of the pulverized coal;

[0018] The determining whether the primary air system is abnormal according to the parameter value of the preset parameter includes:

[0019] determining a maximum temperature rise rate of the primary air system according to the volatile matter content of the pulverized coal;

[0020] comparing the primary air temperature rise rate of the coal mill with the maximum temperature rise rate of the primary air system;

[0021] Determine whether the primary air system is abnormal based on the comparison results.

[0022] In one embodiment, when the abnormality type is valve failure, determining the corresponding preset parameters according to the abnormality type includes:

[0023] According to the preset corresponding relationship table, the preset parameters corresponding to the valve failure are determined to be the valve opening of the hot primary air regulating valve and the valve opening of the cold primary air regulating valve of the coal mill;

[0024] The determining whether the primary air system is abnormal according to the parameter value of the preset parameter includes:

[0025] Determining a flow adjustment coefficient of the hot primary air adjustment valve and a flow adjustment coefficient of the cold primary air adjustment valve according to the valve opening of the hot primary air adjustment valve and the valve opening of the cold primary air adjustment valve of the coal mill;

[0026] Calculating a theoretical value of hot primary air flow and a theoretical value of cold primary air flow according to the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve;

[0027] Calculate the theoretical value of mixed primary air flow rate and the theoretical value of mixed primary air temperature according to the theoretical value of hot primary air flow rate and the theoretical value of cold primary air flow rate;

[0028] Comparing the theoretical value of the mixed primary air flow rate with the actual value of the mixed primary air flow rate, and comparing the theoretical value of the mixed primary air temperature with the actual value of the mixed primary air temperature;

[0029] Determine whether the primary air system is abnormal based on the comparison results.

[0030] In one embodiment, the calculating of the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate according to the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve includes:

[0031] Substitute the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve into the following primary air flow prediction model to determine the theoretical value of the hot primary air flow and the theoretical value of the cold primary air flow:

[0032]

[0033] Among them, Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of cold primary air flow; C v h C is the flow coefficient of the hot primary air adjustment valve; v c P is the flow coefficient of the cold primary air adjustment valve; h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; P mix is the pressure of the mixed primary air; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0034] The calculating of the mixed primary air flow theoretical value and the mixed primary air temperature theoretical value according to the hot primary air flow theoretical value and the cold primary air flow theoretical value comprises:

[0035] Substitute the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate into the following formula to determine the theoretical value of the mixed primary air flow rate and the theoretical value of the mixed primary air temperature:

[0036] Q mix =Q h +Q C ;

[0037]

[0038] Among them, Q mix is the theoretical value of mixed primary air flow; Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of the cold primary air flow rate; T mix is the theoretical value of mixed primary air temperature; P h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; T h is the hot primary air inlet temperature; T c is the cold primary air inlet temperature; ρ h is the hot primary air density; ρc is the density of cold primary air.

[0039] In one embodiment, comparing the theoretical value of the mixed primary air flow rate with the actual value of the mixed primary air flow rate, and comparing the theoretical value of the mixed primary air temperature with the actual value of the mixed primary air temperature, includes:

[0040] Determine the ratio of the deviation between the theoretical value of the mixed primary air flow and the actual value of the mixed primary air flow to the theoretical value of the mixed primary air flow as a first comparison result;

[0041] Determining a deviation between the theoretical value of the mixed primary air temperature and the actual value of the mixed primary air temperature as a second comparison result;

[0042] The determining whether the primary air system is abnormal according to the comparison result includes:

[0043] When the first comparison result is greater than a preset proportional coefficient or the second comparison result is greater than a preset temperature deviation value, it is determined that the primary air system is abnormal.

[0044] In one embodiment, when the abnormality type is a stuck valve, determining the corresponding preset parameters according to the abnormality type includes:

[0045] According to the preset corresponding relationship table, the preset parameters corresponding to the valve jam are determined to be the valve opening command value and the valve opening actual value of the coal mill primary air regulating valve;

[0046] The determining whether the primary air system is abnormal according to the parameter value of the preset parameter includes:

[0047] Calculating the variance between the valve opening command value and the valve opening actual value of the primary air regulating valve according to the parameter value of the preset parameter;

[0048] When the variance between the valve opening command value and the valve opening actual measurement value of the primary air regulating valve is greater than a preset variance threshold, it is determined that the primary air system is abnormal.

[0049] The present application also provides a coal mill primary air system safety alarm device, comprising:

[0050] an acquisition module, configured to acquire a primary air system abnormality type that causes spontaneous combustion of pulverized coal in a coal mill, wherein the abnormality type includes at least one of abnormal air temperature, abnormal temperature rise rate, valve failure, and valve jamming;

[0051] A determination module, configured to determine corresponding preset parameters according to the abnormality type;

[0052] a judgment module, configured to judge whether the primary air system is abnormal according to the parameter value of the preset parameter;

[0053] The alarm module is used to issue an alarm message that the coal powder in the pulverizer has a risk of spontaneous combustion when an abnormality occurs in the primary air system.

[0054] In one embodiment, when the abnormality type is abnormal wind temperature, the determination module is configured to:

[0055] It is used to determine that the preset parameter corresponding to the abnormal wind temperature is the volatile matter content of the pulverized coal according to the preset corresponding relationship table;

[0056] The judgment module includes:

[0057] A first determining submodule is configured to determine the primary air explosion temperature of the coal mill according to the volatile matter content of the pulverized coal;

[0058] A first comparison submodule is configured to compare the primary air inlet temperature of the coal mill with the primary air explosion temperature of the coal mill;

[0059] The first judgment submodule is used to judge whether the primary air system is abnormal according to the comparison result.

[0060] In one embodiment, when the abnormality type is abnormal temperature rise rate, the determining module is configured to:

[0061] According to the preset corresponding relationship table, the preset parameter corresponding to the abnormal temperature rise rate is determined to be the volatile matter content of the pulverized coal;

[0062] The judgment module includes:

[0063] A second determining submodule is configured to determine a maximum temperature rise rate of the primary air system according to the volatile matter content of the pulverized coal;

[0064] A second comparison submodule is used to compare the primary air temperature rise rate of the coal mill with the maximum temperature rise rate of the primary air system;

[0065] The second judgment submodule is used to judge whether the primary air system is abnormal according to the comparison result.

[0066] In one embodiment, when the abnormality type is valve failure, the determining module is configured to:

[0067] According to the preset corresponding relationship table, the preset parameters corresponding to the valve failure are determined to be the valve opening of the hot primary air regulating valve and the valve opening of the cold primary air regulating valve of the coal mill;

[0068] The judgment module includes:

[0069] a third determining submodule, configured to determine a flow adjustment coefficient of the hot primary air regulating valve and a flow adjustment coefficient of the cold primary air regulating valve according to the valve opening of the hot primary air regulating valve and the valve opening of the cold primary air regulating valve of the coal mill;

[0070] A first calculation submodule is configured to calculate a theoretical value of hot primary air flow and a theoretical value of cold primary air flow according to the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve;

[0071] A second calculation submodule is used to calculate a theoretical value of mixed primary air flow and a theoretical value of mixed primary air temperature according to the theoretical value of hot primary air flow and the theoretical value of cold primary air flow;

[0072] A third comparison submodule is configured to compare the theoretical value of the mixed primary air flow rate with the actual value of the mixed primary air flow rate, and to compare the theoretical value of the mixed primary air temperature with the actual value of the mixed primary air temperature;

[0073] The third judgment submodule is used to judge whether the primary air system is abnormal according to the comparison result.

[0074] In one embodiment, the first calculation submodule is configured to:

[0075] Substitute the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve into the following primary air flow prediction model to determine the theoretical value of the hot primary air flow and the theoretical value of the cold primary air flow:

[0076]

[0077] Among them, Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of cold primary air flow; C v h C is the flow coefficient of the hot primary air adjustment valve; v c P is the flow coefficient of the cold primary air adjustment valve; h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; P mix is the pressure of the mixed primary air; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0078] The second calculation submodule is configured to:

[0079] Substitute the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate into the following formula to determine the theoretical value of the mixed primary air flow rate and the theoretical value of the mixed primary air temperature:

[0080] Q mix =Q h +Q C ;

[0081]

[0082] Among them, Q mix is the theoretical value of mixed primary air flow; Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of the cold primary air flow rate; T mix is the theoretical value of mixed primary air temperature; P h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; T h is the hot primary air inlet temperature; T c is the cold primary air inlet temperature; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0083] In one embodiment, the third comparison submodule is used to:

[0084] Determine the ratio of the deviation between the theoretical value of the mixed primary air flow and the actual value of the mixed primary air flow to the theoretical value of the mixed primary air flow as a first comparison result;

[0085] Determining a deviation between the theoretical value of the mixed primary air temperature and the actual value of the mixed primary air temperature as a second comparison result;

[0086] The third judgment submodule is further configured to:

[0087] When the first comparison result is greater than a preset proportional coefficient or the second comparison result is greater than a preset temperature deviation value, it is determined that the primary air system is abnormal.

[0088] In one embodiment, when the abnormality type is valve jamming, the determining module is configured to:

[0089] According to the preset corresponding relationship table, the preset parameters corresponding to the valve jam are determined to be the valve opening command value and the valve opening actual value of the coal mill primary air regulating valve;

[0090] The judgment module includes:

[0091] a third calculation submodule, configured to calculate a variance between a valve opening command value and a valve opening actual value of the primary air regulating valve according to a parameter value of the preset parameter;

[0092] The fourth determining submodule is configured to determine that the primary air system is abnormal when a variance between the valve opening command value and the valve opening actual value of the primary air regulating valve is greater than a preset variance threshold.

[0093] The present application also provides a coal mill primary air system safety alarm system, comprising:

[0094] at least one processor; and,

[0095] a memory communicatively connected to the at least one processor; wherein,

[0096] The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to implement the coal mill primary air system safety alarm method recorded in any of the above embodiments.

[0097] The present application also provides a computer-readable storage medium. When the instructions in the storage medium are executed by the processor corresponding to the coal mill primary air system safety alarm system, the coal mill primary air system safety alarm system can implement the coal mill primary air system safety alarm method recorded in any of the above embodiments.

[0098] The beneficial effects of the present application are as follows: the present application determines whether the primary air system is abnormal based on the abnormal type of the primary air system of the coal powder spontaneous combustion of the coal mill, and based on the parameter value of the preset parameter corresponding to the abnormal type, and issues an early warning. The present application determines the corresponding preset parameters based on the abnormal type existing in the primary air system, and identifies multiple abnormal situations respectively, avoiding the situation where the adaptability is poor and false alarms are easy to occur due to a single parameter, and improving the accuracy of the coal mill safety early warning. The present application also determines the primary air explosion temperature of the coal mill and the maximum temperature rise rate of the primary air system based on the volatile matter content of the coal powder, realizing an upgrade from static empirical control with a fixed threshold to dynamic and precise prevention and control, preventing the risk of spontaneous combustion and explosion, and improving the safety of the primary air system of the coal mill. In addition, the present application not only identifies and alarms for valve jamming, but also identifies and alarms for valve failure, avoiding the dangerous situation where the valve appears normal but actually fails, and further improving the safety of the primary air system of the coal mill.

[0099] Other features and advantages of the present application will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present application. The purposes and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0100] The technical solution of the present application is further described in detail below through the accompanying drawings and examples. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] The accompanying drawings are used to provide a further understanding of the present application and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the present application and do not constitute a limitation of the present application. In the accompanying drawings:

[0102] Figure 1 This is a flow chart of a safety alarm method for a primary air system of a coal mill in one embodiment of the present application;

[0103] Figure 2 This is a structural diagram of a safety alarm device for a primary air system of a coal mill in one embodiment of the present application;

[0104] Figure 3 This is a schematic diagram of the hardware structure of a coal mill primary air system safety alarm system in one embodiment of the present application. DETAILED DESCRIPTION

[0105] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application and are not used to limit the present application.

[0106] Figure 1 This is a flow chart of a safety alarm method for a coal mill primary air system in one embodiment of the present application. Figure 1 As shown, the method can be implemented as the following steps S101-:

[0107] In step S101, the primary air system abnormality type that causes coal powder spontaneous combustion in the coal mill is obtained, wherein the abnormality type includes at least abnormal air temperature, abnormal temperature rise rate, valve failure, and valve jamming;

[0108] In step S102, corresponding preset parameters are determined according to the abnormality type;

[0109] In step S103, judging whether the primary air system is abnormal according to the parameter value of the preset parameter;

[0110] In step S104, when an abnormality occurs in the primary air system, an alarm message is issued indicating that there is a risk of spontaneous combustion of coal powder in the pulverizer.

[0111] In this application, the type of abnormality in the primary air system that causes spontaneous combustion of coal powder in the coal mill is obtained. The primary air at the inlet of the medium-speed coal mill is a mixture of hot primary air and cold primary air. The system is equipped with a hot primary air electric regulating valve and an electric cold primary air regulating valve, which are used to control the flow of hot primary air and cold primary air respectively, and then control the flow and temperature of the mixed primary air. If the flow and / or temperature of the primary air deviates from the normal state, it may cause spontaneous combustion or explosion in the medium-speed mill. Therefore, it is necessary to perform safety fault detection on the primary air system.

[0112] The failure of the primary air system mainly includes the following aspects:

[0113] (1) Abnormal wind temperature

[0114] Excessively high primary air temperatures at the inlet of a medium-speed mill can easily lead to spontaneous combustion or deflagration. When the primary air temperature exceeds the design value, it accelerates the drying of the pulverized coal, causing volatiles (such as CO and CH4) to precipitate prematurely within the mill. When the concentration of volatiles reaches the explosion limit, exposure to high temperatures or sparks can easily trigger a deflagration.

[0115] (2) Abnormal temperature rise rate

[0116] The temperature rise rate of the primary air at the inlet of the medium-speed grinding mill is too fast, resulting in the rapid release of volatiles. Specifically, the volatile matter release rate of coal is exponentially related to temperature. When the temperature rise rate exceeds 5°C / min (bituminous coal), the volatile matter may precipitate in large quantities in a short period of time, causing the local concentration to exceed the lower explosion limit, thereby causing an explosion. For lignite, lignite has higher volatile matter and lower auto-ignition temperature, so its temperature rise rate usually needs to be more stringent (3°C / min) to avoid explosions caused by excessive temperature rise. In actual operation, various types of coal are often used for mixed combustion. The limit of the temperature rise rate is not a fixed value, but the upper limit of the temperature rise needs to be determined based on the amount of volatile matter in the coal.

[0117] (3) Valve stuck or valve failure

[0118] Valve jamming or failure can lead to uncontrolled primary air flow and temperature. Prolonged use of hot or cold primary air regulating valves often leads to valve jamming and wear. A jammed valve can cause regulation lag, or even failure to achieve the desired regulation target, leading to inlet temperature exceeding the limit. Valve wear can reduce or even completely lose regulation function. The actuator may indicate normal valve opening and the actuation signal is consistent, but changes in valve opening do not result in changes in flow. This indicates a valve failure, which poses a risk of loss of temperature or flow control and requires an early warning.

[0119] Therefore, in this application, the abnormality types include at least abnormal wind temperature, abnormal temperature rise rate, valve failure and valve jam. Of course, other abnormality types can also be added and analyzed accordingly based on the solution of this application.

[0120] The corresponding preset parameters are determined according to the abnormality type. In the present application, a correspondence table is pre-established for different abnormality types to extract the corresponding preset parameters for subsequent analysis. Specifically, the preset parameter corresponding to the wind temperature abnormality is the volatile matter content of the coal powder; the preset parameter corresponding to the temperature rise rate abnormality is the volatile matter content of the coal powder; the preset parameters corresponding to the valve failure are the valve opening of the hot primary air regulating valve of the coal mill, the valve opening of the cold primary air regulating valve, the hot primary air inlet temperature, the cold primary air inlet temperature, the hot primary air inlet pressure, and the cold primary air inlet pressure of the coal mill; the preset parameters corresponding to the valve jam are the valve opening instruction value and the valve opening actual value of the primary air regulating valve of the coal mill.

[0121] Determine whether the primary air system is abnormal based on the parameter value of the preset parameter. The judgment process for each type of abnormality is as follows:

[0122] (1) Air temperature detection

[0123] The rapid increase in the temperature of the primary air at the inlet of the medium-speed coal mill can easily cause the coal powder in the coal mill to spontaneously combust or explode. Therefore, this application determines the explosion temperature based on the source of the coal powder, and issues an alarm when it is higher than the explosion temperature. In addition, since the volatile content V is not an online value, but intermittent data regularly tested by the team members, the data cannot be automatically updated in the DCS system, and the volatile content data can only be input regularly by the operator. In order to provide continuous online data, this application installs an online instrument for the coal feeder to measure the volatile content of the coal powder, and then determines the primary air explosion temperature of the coal mill based on the volatile content of the coal powder. In this application, the volatile content and explosion temperature of a variety of coal powders are obtained in advance based on the test data, and the volatile content and explosion temperature of a variety of coal powders are fitted to obtain the functional relationship between the volatile content and the explosion temperature:

[0124] T 爆燃 =f(V);

[0125] Among them, T 爆燃 is the primary air explosion temperature; V is the volatile matter content in the coal powder.

[0126] In one embodiment, the functional relationship between the volatile matter content and the deflagration temperature is:

[0127] T 爆燃 =a·e -bV +c;

[0128] Among them, T 爆燃 is the primary air explosion temperature; V is the volatile matter content in the coal powder; parameters a, b, and c can be determined by fitting experimental data.

[0129] This model has few parameters to fit, is simple, and is suitable for rapid estimation. It exhibits strong fitting stability for small amounts of data (e.g., fewer than 10 data sets) and is less prone to overfitting. Here, a corresponds to the theoretical limit temperature in the absence of volatiles (approximately the fixed carbon ignition point); b reflects the accelerating effect of volatiles on the burning rate; and c represents the lower temperature limit (related to the ash thermal resistance).

[0130] In another embodiment, the functional relationship between the volatile matter content and the deflagration temperature is:

[0131]

[0132] Among them, T 爆燃 is the primary air explosion temperature; V is the volatile matter content in the coal powder; parameters a, b, c, d, e, f, g, and h can be determined by fitting experimental data.

[0133] The model establishes functional relationships in segments, improving the accuracy of model predictions. For low-volatility zones, it reflects nonlinear decay characteristics; for medium-volatility zones, it reflects the linear relationship between volatile release and temperature drop; and for high-volatility zones, it reflects rapid convergence characteristics.

[0134] Furthermore, through the method provided by the present application, the deflagration temperature threshold is no longer a fixed value, but a variable that changes according to the type of coal.

[0135] After determining the deflagration temperature, obtaining the primary air inlet temperature of the coal mill; comparing the primary air inlet temperature of the coal mill with the primary air deflagration temperature of the coal mill; and judging whether the primary air system is abnormal based on the comparison result.

[0136] Specifically, in this application, a corresponding temperature threshold is set according to the deflagration temperature. When the primary air inlet temperature of the coal mill is greater than the temperature threshold, the primary air system is determined to be abnormal. Furthermore, this application sets multiple temperature preset values ​​according to the deflagration temperature to issue three levels of alarms for excessive primary air temperature according to the degree of urgency:

[0137] ① When the primary air inlet temperature is greater than the first preset value and lower than the second preset value and maintains the preset time, the alarm type is determined to be a primary air temperature level 1 alarm; for example, when T 爆燃 -10<T 一次风 <T 爆燃 -5, and it lasts for more than 3 seconds, the alarm message "explosion temperature is about to be reached, level 1 alarm" will be sent;

[0138] ② When the primary air inlet temperature is greater than the second preset value and lower than the deflagration temperature and maintains the preset time, the alarm type is determined to be a primary air temperature level 2 alarm; for example, when T 爆燃 -5<T 一次风 <T 爆燃 , and keep it for more than 3 seconds, send the alarm message "explosion temperature is about to reach the second level alarm";

[0139] ③When the primary air inlet temperature is greater than or equal to the deflagration temperature, that is, when T 一次风 >T 爆燃 , determine that the alarm type is a three-level wind temperature alarm, send the alarm message "explosion temperature has been reached", and start the emergency stop procedure.

[0140] (2) Temperature rise rate detection

[0141] If the primary air temperature of the pulverizer rises too quickly, there is also a risk of deflagration, so there is a limit on the temperature rise rate exceeding 5℃ / min (bituminous coal, 3℃ / min for lignite). However, this is a rough engineering setting. In fact, the temperature rise limit value for mixed coal types is variable and is still related to the volatile matter. The higher the volatile matter, the lower the temperature rate requirement, and vice versa.

[0142] To determine whether the primary air system is abnormal based on the parameter values ​​of the preset parameters, it is necessary to first determine the maximum temperature rise rate of the primary air system based on the volatile matter content of the pulverized coal. Specifically, a functional relationship between the volatile matter content of the pulverized coal and the maximum temperature rise rate is obtained by fitting experimental data in advance:

[0143] α max =f(V);

[0144] Among them, α max is the maximum temperature rise rate; V is the volatile matter content in coal powder.

[0145] In one embodiment, the functional relationship between the volatile matter content of the pulverized coal and the maximum temperature rise rate is as follows:

[0146]

[0147] Among them, α max is the maximum temperature rise rate; V is the volatile matter content in the pulverized coal; the parameters k, α0, and β can be obtained by fitting the experimental data, k is the rate attenuation coefficient, α0 is the volatile matter offset, and β is the reference rate.

[0148] After determining the maximum temperature rise rate, the primary air temperature rise rate of the coal mill is obtained, and the primary air temperature rise rate of the coal mill is compared with the maximum temperature rise rate of the primary air system. Specifically, the present application sets a temperature rise rate threshold according to the temperature rise rate. When the primary air temperature rise rate is greater than the temperature rise rate threshold, the temperature rise rate is determined to be abnormal, and the corresponding alarm type is determined based on the comparison result. In the present application, two levels of alarm are set for abnormal temperature rise rate:

[0149] When the primary air temperature rise rate is greater than the first temperature rise rate warning threshold and less than the maximum temperature rise rate, and the second preset time is maintained, the alarm type is determined to be a temperature rise rate level 1 alarm. For example, when α max >α>α max -0.2, and keep it for more than 3 seconds, the alarm message "the upper limit of temperature rise is about to be reached, level 1 alarm" will be sent.

[0150] When the primary air temperature rise rate is greater than or equal to the maximum temperature rise rate and is maintained for a second preset time, the alarm type is determined to be a temperature rise rate level 2 alarm, and the hot primary air volume is reduced; for example, when α≥α max, and keep it for more than 3 seconds, reduce the hot air volume once, and reduce the temperature rise to below the alarm value.

[0151] (3) Valve jam detection

[0152] Under normal circumstances, the valve opening command and feedback are consistent, with the deviation between the two being essentially zero. When a valve is stuck, the valve opening feedback and the opening command become mismatched. A typical situation is when the difference between the opening and the measured value fluctuates, often failing to reach zero. Another situation is when the feedback remains unchanged regardless of the command, indicating severe valve sticking.

[0153] Therefore, the preset parameters corresponding to the valve sticking are determined to be the valve opening command value and the valve opening actual value of the coal mill primary air regulating valve;

[0154] The method of judging whether the primary air system is abnormal based on the parameter value of the preset parameter is as follows: specifically, calculating the variance of the valve opening instruction value and the actual valve opening value of the primary air regulating valve; then, comparing the equation with the preset variance threshold, wherein the preset variance threshold can be determined based on data under historical normal conditions, such as the standard deviation of the valve opening instruction value and the actual valve opening value of the primary air regulating valve under historical normal working conditions. Furthermore, when the variance is greater than the preset variance threshold (for example, three standard deviations), it is determined that the primary air system is abnormal and the primary air regulating valve is stuck. It is understandable that the valve stuck here can be analyzed and determined for the valve stuck of the hot primary air regulating valve and the valve stuck of the cold primary air regulating valve respectively.

[0155] Furthermore, in the present application, a two-level alarm is performed for valve sticking. When the variance is greater than a preset variance threshold, it is determined to be a first-level sticking. When, under the premise of first-level sticking, the actual measured value of the valve opening remains unchanged for a long time within a preset time period, that is, it does not change with the change of the valve instruction, it is determined to be a second-level sticking.

[0156] For example, the data 600 seconds before the timing point (once per second) is used to calculate the variance of the difference between the opening command and the measured value. If it exceeds three standard deviations under normal operating conditions, it is beyond the normal range and can be determined as a level one jam. On the premise of meeting the level one jam, if the measured value remains unchanged for a long time (the data 600 seconds before the current point can be used for judgment), it is determined as a level two jam.

[0157] (4) Valve failure detection

[0158] Valve failure is difficult to determine. For example, if the valve connecting rod falls off, the valve core is severely worn, or the valve leaks, no matter how the actuator operates, even if the feedback is normal, the actual flow rate of the valve will not change much or even not change. This effect can be called a failure. Valve failure is more dangerous. The apparent normal state masks the possibility of an impending crisis, such as a rapid increase in temperature. Therefore, this application calculates the theoretical flow rate and temperature of the mixed primary air formed by mixing hot primary air and cold primary air, and compares the theoretical values ​​with the actual values ​​to determine whether the valve has failed.

[0159] Therefore, when the target detection is valve failure detection, the preset parameters are the valve opening of the hot primary air regulating valve and the valve opening of the cold primary air regulating valve of the coal mill determined according to the preset corresponding relationship table.

[0160] Specifically, judging whether the primary air system is abnormal based on the parameter value of the preset parameter includes: determining the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve based on the valve opening of the hot primary air adjustment valve and the valve opening of the cold primary air adjustment valve of the coal mill; for example, querying a pre-stored first correspondence table based on the valve opening of the hot primary air adjustment valve and the valve opening of the cold primary air adjustment valve to determine the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve.

[0161] Then, the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate are calculated based on the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve. For example, the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve are respectively substituted into the following primary air flow prediction model to determine the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate:

[0162]

[0163] Among them, Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of cold primary air flow; C v h C is the flow coefficient of the hot primary air adjustment valve; v c P is the flow coefficient of the cold primary air adjustment valve; h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; P mix is the pressure of the mixed primary air; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0164] For ρ h and ρ c The inlet air temperature and pressure can be measured in real time and calculated using the following formula:

[0165] ρ h =P h / (RT h ),ρ c =P c / (RT c );

[0166] Among them, ρ h is the hot primary air density; ρ c is the density of cold primary air; P h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; T h is the hot primary air inlet temperature; T c is the cold primary air inlet temperature; R is the gas constant.

[0167] Furthermore, the theoretical value of the mixed primary air flow rate and the theoretical value of the mixed primary air temperature can be calculated based on the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate. For example, the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate are substituted into the following formula to determine the theoretical value of the mixed primary air flow rate and the theoretical value of the mixed primary air temperature:

[0168] Q mix =Q h +Q C ;

[0169]

[0170] Among them, Q mix is the theoretical value of mixed primary air flow; Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of the cold primary air flow rate; T mix is the theoretical value of mixed primary air temperature; P h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; T h is the hot primary air inlet temperature; T c is the cold primary air inlet temperature; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0171] Compare the theoretical value of the mixed primary air flow rate with the actual value of the mixed primary air flow rate, and compare the theoretical value of the mixed primary air temperature with the actual value of the mixed primary air temperature. This application considers the two valves as a whole. As long as one of the valves has a problem, it will cause temperature and flow abnormalities. When the valve fails, the first thing affected is the mixed primary air flow rate, which may be too large or too small, and then the mixed primary air temperature. The temperature has a large inertia relative to the flow rate, and it takes a certain amount of time to react. According to the above characteristics, this application detects valve failure. Specifically, it determines that the ratio of the deviation between the theoretical value of the mixed primary air flow rate and the actual value of the mixed primary air flow rate to the theoretical value of the mixed primary air flow rate is the first comparison result; and determines that the deviation between the theoretical value of the mixed primary air temperature and the actual value of the mixed primary air temperature is the second comparison result. The method of judging whether the primary air system is abnormal based on the comparison results includes:

[0172] When the first comparison result is greater than a preset proportional coefficient or the second comparison result is greater than a preset temperature deviation value, the primary air system is determined to be abnormal. Specifically, when the first comparison result exceeds a preset ratio of the theoretical mixed primary air flow rate, the alarm type is determined to be a level one failure alarm for the hot primary air adjustment valve and the cold primary air adjustment valve; when the second comparison result is greater than a first preset temperature deviation value, the alarm type is determined to be a level two failure alarm for the hot primary air adjustment valve and the cold primary air adjustment valve; and when the second comparison result is greater than a second preset temperature deviation value, the alarm type is determined to be a level three failure alarm for the hot primary air adjustment valve and the cold primary air adjustment valve.

[0173] For example, when |Q mix理论 -Q mix实际 | / Q mix理论 >10%, it is the first level failure alarm of hot primary air regulating valve and cold primary air regulating valve; when |T mix理论 -T mix实际 |>5℃, it is the second-level failure alarm of hot primary air regulating valve and cold primary air regulating valve; when |T mix实际 -T mix理论 |>10℃, it is the third-level failure alarm of the hot primary air regulating valve and the cold primary air regulating valve.

[0174] In this application, it should be noted that the hot primary air adjustment valve flow coefficient C v h Flow coefficient C of cold primary air regulating valve v cAlthough calculated from the valve inlet and outlet parameters, they do not depend on the mixed parameters (flow and temperature). The mixed parameters are only the result of the mixing. They are only related to the inlet temperature, flow and opening. Therefore, each pair of inlet temperature, flow and opening can be mapped to an outlet mixed flow and temperature. In this way, a mapping table can be established to achieve C v h and C v c Real-time calculation.

[0175] In one embodiment of the present application, the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve are determined according to the valve opening of the hot primary air adjustment valve and the valve opening of the cold primary air adjustment valve of the coal mill; for example, a pre-stored first correspondence table is queried according to the valve opening of the hot primary air adjustment valve and the valve opening of the cold primary air adjustment valve to determine the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve, wherein the first correspondence table stores the correspondence between valve opening combinations and flow adjustment coefficient combinations.

[0176] In another embodiment of the present application, since each real-time state can obtain an inlet pressure combination (P h ,P c ), inlet temperature combination (T h ,T c ) and valve opening combination (θ h ,θ c ), therefore, the target operating condition that is closest to the operating condition can be selected in the correspondence table to determine the corresponding flow adjustment coefficient. At this time, the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve are determined according to the valve opening of the hot primary air adjustment valve and the valve opening of the cold primary air adjustment valve of the coal mill, including: obtaining the inlet pressure combination and inlet temperature combination of the hot primary air and the cold primary air corresponding to the valve opening combination at the current moment; forming an operating condition characteristic vector from the valve opening combination and the inlet pressure combination and the inlet temperature combination; matching the operating condition characteristic vector with the operating condition characteristic vectors under each standard operating condition in a pre-stored second correspondence table to determine the target operating condition corresponding to the operating condition characteristic vector, wherein the second correspondence table stores the correspondence between the operating condition characteristic vector under the standard operating condition and the flow adjustment coefficient combination; determining the flow adjustment coefficient combination of the target operating condition as the flow adjustment coefficient combination of the hot primary air adjustment valve and the cold primary air adjustment valve.

[0177] For example, matching the operating condition characteristic vector with the operating condition characteristic vectors for each standard operating condition in a pre-stored second correspondence table to determine the target operating condition corresponding to the operating condition characteristic vector may include: calculating the deviation between each element in the operating condition characteristic vector and the corresponding element in the operating condition characteristic vector for each standard operating condition in the pre-stored second correspondence table; determining as a candidate operating condition the standard operating condition in which all deviations are less than a preset deviation threshold; and determining as the target operating condition the operating condition with the smallest deviation among the candidate operating conditions. For example, searching for an operating condition in which the absolute differences between the six points are no greater than 5%, and selecting the operating condition with the smallest deviation as the target operating condition.

[0178] Of course, matching the operating condition characteristic vector with the operating condition characteristic vectors under each standard operating condition in the pre-stored second correspondence table to determine the target operating condition corresponding to the operating condition characteristic vector can also be: calculating the similarity between the operating condition characteristic vector and the operating condition characteristic vectors under each standard operating condition in the pre-stored second correspondence table; and determining the standard operating condition with the highest similarity as the target operating condition.

[0179] In this embodiment, the second correspondence table is constructed in the following manner: obtaining the valve opening combination of the hot primary air regulating valve and the cold primary air regulating valve under standard working conditions and the corresponding historical parameter data, wherein the historical parameter data at least includes the inlet pressure combination of the hot primary air and the cold primary air, the inlet temperature combination of the hot primary air and the cold primary air, and the measured value of the mixed primary air pressure, the measured value of the mixed primary air flow rate, and the measured value of the mixed primary air temperature; calculating the wind density combination of the hot primary air and the cold primary air, the wind flow combination of the hot primary air and the cold primary air, the hot primary air regulating valve opening combination and the corresponding historical parameter data according to the historical data. and the differential pressure combination of the hot primary air regulating valve; calculate the flow adjustment coefficient combination of the hot primary air regulating valve and the cold primary air regulating valve according to the wind density combination of the hot primary air and the cold primary air, the wind flow combination of the hot primary air and the cold primary air, and the differential pressure combination of the hot primary air regulating valve and the cold primary air regulating valve; construct the second correspondence table according to the valve opening combination of the hot primary air regulating valve and the cold primary air regulating valve under the standard working conditions, the inlet pressure combination of the hot primary air and the cold primary air, the inlet temperature combination of the hot primary air regulating valve and the cold primary air regulating valve and the flow adjustment coefficient combination of the hot primary air regulating valve and the cold primary air regulating valve.

[0180] Specifically, the wind density combination of the hot primary air and the cold primary air is calculated by the following formula:

[0181] ρ h =P h / (RT h ),ρ c =P c / (RT c );

[0182] Among them, ρ h is the hot primary air density; ρ c is the density of cold primary air; P h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; T h is the hot primary air inlet temperature; T c is the cold primary air inlet temperature; R is the gas constant.

[0183] The combined flow rate of hot primary air and cold primary air is calculated using the following formula:

[0184]

[0185] Among them, Q h is the hot primary air flow rate; Q c Q is the cold primary air flow rate; mix is the mixed primary air flow rate; T mix is the mixed primary air temperature; ρ h is the hot primary air density; ρ c is the density of cold primary air; T h is the hot primary air inlet temperature; T c It is the cold primary air inlet temperature.

[0186] The differential pressure combination of the hot primary air regulating valve and the cold primary air regulating valve is calculated by the following formula:

[0187] ΔP h =P h -P mix ,ΔP c =P c -P mix ;

[0188] Where ΔP h The differential pressure between the inlet and outlet of the hot primary air regulating valve; ΔP c P is the differential pressure between the inlet and outlet of the cold primary air regulating valve; h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; P mix is the pressure of the mixed primary air.

[0189] The flow adjustment coefficient combination of the hot primary air adjustment valve and the cold primary air adjustment valve is calculated by the following formula:

[0190]

[0191] Among them, C v h C is the flow coefficient of the hot primary air adjustment valve; v cQ is the flow coefficient of the cold primary air adjustment valve; h is the hot primary air flow rate; Q c is the cold primary air flow rate; ΔP h The differential pressure between the inlet and outlet of the hot primary air regulating valve; ΔP c P is the differential pressure between the inlet and outlet of the cold primary air regulating valve; h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0192] For example, if 1000 historical data are extracted, for each set of data, the opening combination (θh, θc), inlet pressure combination (Ph, Pc), inlet temperature combination (Th, Tc) and flow adjustment coefficient combination (C v h , C v c ) to construct a second correspondence table that can cover all working conditions.

[0193] Furthermore, the alarm type of the primary air system is determined according to the detection result, and corresponding alarm information is issued.

[0194] This application has constructed a safety early warning method for medium-speed coal mills based on dynamic adaptation of coal quality and coordination of multiple parameters. The core is to break through traditional limitations, obtain coal quality characteristics in real time, dynamically adjust the safety thresholds of inlet air temperature and temperature rise rate, and combine the flow-temperature joint model. Through multiple tests, a dynamic safety threshold is adopted to adjust the inlet air temperature upper limit and temperature rise rate limit in real time based on the volatile matter of coal quality, avoiding the "one-size-fits-all" problem of traditional fixed thresholds in mixed coal scenarios, reducing false alarms and missed reports; adopting a multi-level early warning mechanism to achieve risk classification management and early intervention to avoid the expansion of accidents. Command-feedback deviation analysis is used to detect valve jams; flow-temperature model verification is used to identify valve failures; the problem of traditional methods being insensitive to hidden failures (such as valve core wear) is solved to achieve rapid response. Flow abnormalities (small inertia) trigger alarms first, and temperature abnormalities (large inertia) are used as auxiliary verification to shorten the fault confirmation time. Through comprehensive testing, preventive maintenance is achieved, planned maintenance is triggered, and shutdowns caused by sudden failures are avoided, achieving precise safety control and fault early warning.

[0195] The beneficial effects of the present application are as follows: the present application determines whether the primary air system is abnormal based on the abnormal type of the primary air system of the coal powder spontaneous combustion of the coal mill, and based on the parameter value of the preset parameter corresponding to the abnormal type, and issues an early warning. The present application determines the corresponding preset parameters based on the abnormal type existing in the primary air system, and identifies multiple abnormal situations respectively, avoiding the situation where the adaptability is poor and false alarms are easy to occur due to a single parameter, and improving the accuracy of the coal mill safety early warning. The present application also determines the primary air explosion temperature of the coal mill and the maximum temperature rise rate of the primary air system based on the volatile matter content of the coal powder, realizing an upgrade from static empirical control with a fixed threshold to dynamic and precise prevention and control, preventing the risk of spontaneous combustion and explosion, and improving the safety of the primary air system of the coal mill. In addition, the present application not only identifies and alarms for valve jamming, but also identifies and alarms for valve failure, avoiding the dangerous situation where the valve appears normal but actually fails, and further improving the safety of the primary air system of the coal mill.

[0196] In one embodiment, when the abnormality type is abnormal wind temperature, the above step S102 may be implemented as follows:

[0197] According to the preset corresponding relationship table, the preset parameter corresponding to the abnormal wind temperature is determined to be the volatile matter content of the pulverized coal;

[0198] The above step S103 can be implemented as the following steps A1-A3:

[0199] In step A1, the primary air explosion temperature of the coal mill is determined according to the volatile matter content of the coal powder;

[0200] In step A2, the primary air inlet temperature of the coal mill is compared with the primary air explosion temperature of the coal mill;

[0201] In step A3, it is determined whether the primary air system is abnormal based on the comparison result.

[0202] In one embodiment, when the abnormality type is abnormal temperature rise rate, the above step S102 can be implemented as follows:

[0203] According to the preset corresponding relationship table, the preset parameter corresponding to the abnormal temperature rise rate is determined to be the volatile matter content of the pulverized coal;

[0204] The above step S103 can be implemented as the following steps B1-B3:

[0205] In step B1, the maximum temperature rise rate of the primary air system is determined according to the volatile matter content of the pulverized coal;

[0206] In step B2, the primary air temperature rise rate of the coal mill is compared with the maximum temperature rise rate of the primary air system;

[0207] In step B3, it is determined whether the primary air system is abnormal based on the comparison result.

[0208] In one embodiment, when the abnormality type is valve failure, the above step S102 may be implemented as follows:

[0209] According to the preset corresponding relationship table, the preset parameters corresponding to the valve failure are determined to be the valve opening of the hot primary air regulating valve and the valve opening of the cold primary air regulating valve of the coal mill;

[0210] The above step S103 can be implemented as the following steps C1-C5:

[0211] In step C1, the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve are determined according to the valve opening of the hot primary air adjustment valve and the valve opening of the cold primary air adjustment valve of the coal mill;

[0212] In step C2, a theoretical value of the hot primary air flow rate and a theoretical value of the cold primary air flow rate are calculated according to the flow rate adjustment coefficient of the hot primary air adjustment valve and the flow rate adjustment coefficient of the cold primary air adjustment valve;

[0213] In step C3, a theoretical value of mixed primary air flow rate and a theoretical value of mixed primary air temperature are calculated based on the theoretical value of hot primary air flow rate and the theoretical value of cold primary air flow rate;

[0214] In step C4, the theoretical value of the mixed primary air flow rate is compared with the actual value of the mixed primary air flow rate, and the theoretical value of the mixed primary air temperature is compared with the actual value of the mixed primary air temperature;

[0215] In step C5, it is determined whether the primary air system is abnormal based on the comparison result.

[0216] In one embodiment, the above step C2 may be implemented as follows:

[0217] Substitute the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve into the following primary air flow prediction model to determine the theoretical value of the hot primary air flow and the theoretical value of the cold primary air flow:

[0218]

[0219] Among them, Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of cold primary air flow; C v h C is the flow coefficient of the hot primary air adjustment valve; v c P is the flow coefficient of the cold primary air adjustment valve; h is the hot primary air inlet pressure; Pc is the cold primary air inlet pressure; P mix is the pressure of the mixed primary air; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0220] The above step C3 can be implemented as follows:

[0221] Substitute the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate into the following formula to determine the theoretical value of the mixed primary air flow rate and the theoretical value of the mixed primary air temperature:

[0222] Q mix =Q h +Q C ;

[0223]

[0224] Among them, Q mix is the theoretical value of mixed primary air flow; Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of the cold primary air flow rate; T mix is the theoretical value of mixed primary air temperature; P h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; T h is the hot primary air inlet temperature; T c is the cold primary air inlet temperature; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0225] In one embodiment, the above step C4 may be implemented as the following steps C41-C42:

[0226] In step C41, the ratio of the deviation between the theoretical value of the mixed primary air flow and the actual value of the mixed primary air flow to the theoretical value of the mixed primary air flow is determined as a first comparison result;

[0227] In step C42, the deviation between the theoretical value of the mixed primary air temperature and the actual value of the mixed primary air temperature is determined as a second comparison result;

[0228] The above step C5 can be implemented as follows:

[0229] When the first comparison result is greater than a preset proportional coefficient or the second comparison result is greater than a preset temperature deviation value, it is determined that the primary air system is abnormal.

[0230] In one embodiment, when the abnormality type is valve jamming, the above step S102 may be implemented as follows:

[0231] According to the preset corresponding relationship table, the preset parameters corresponding to the valve jam are determined to be the valve opening command value and the valve opening actual value of the coal mill primary air regulating valve;

[0232] The above step S103 can be implemented as the following steps D1-D2:

[0233] In step D1, the variance between the valve opening command value and the valve opening actual value of the primary air regulating valve is calculated according to the parameter value of the preset parameter;

[0234] In step D2, when the variance between the valve opening command value and the valve opening actual value of the primary air regulating valve is greater than a preset variance threshold, it is determined that the primary air system is abnormal.

[0235] Figure 2 FIG. 1 is a schematic structural diagram of a safety alarm device for a primary air system of a coal mill according to an embodiment of the present application. Figure 2 As shown, the device includes:

[0236] An acquisition module 201 is configured to acquire a primary air system abnormality type that causes spontaneous combustion of pulverized coal in a coal mill, wherein the abnormality type includes at least one of abnormal air temperature, abnormal temperature rise rate, valve failure, and valve jamming;

[0237] Determination module 202, for determining corresponding preset parameters according to the abnormality type;

[0238] A judgment module 203 is configured to judge whether the primary air system is abnormal according to the parameter value of the preset parameter;

[0239] The alarm module 204 is configured to issue an alarm message indicating that there is a risk of spontaneous combustion of pulverized coal in the pulverizer when an abnormality occurs in the primary air system.

[0240] In one embodiment, when the abnormality type is abnormal wind temperature, the determination module is configured to:

[0241] It is used to determine that the preset parameter corresponding to the abnormal wind temperature is the volatile matter content of the pulverized coal according to the preset corresponding relationship table;

[0242] The judgment module includes:

[0243] A first determining submodule is configured to determine the primary air explosion temperature of the coal mill according to the volatile matter content of the pulverized coal;

[0244] A first comparison submodule is configured to compare the primary air inlet temperature of the coal mill with the primary air explosion temperature of the coal mill;

[0245] The first judgment submodule is used to judge whether the primary air system is abnormal according to the comparison result.

[0246] In one embodiment, when the abnormality type is abnormal temperature rise rate, the determining module is configured to:

[0247] According to the preset corresponding relationship table, the preset parameter corresponding to the abnormal temperature rise rate is determined to be the volatile matter content of the pulverized coal;

[0248] The judgment module includes:

[0249] A second determining submodule is configured to determine a maximum temperature rise rate of the primary air system according to the volatile matter content of the pulverized coal;

[0250] A second comparison submodule is used to compare the primary air temperature rise rate of the coal mill with the maximum temperature rise rate of the primary air system;

[0251] The second judgment submodule is used to judge whether the primary air system is abnormal according to the comparison result.

[0252] In one embodiment, when the abnormality type is valve failure, the determining module is configured to:

[0253] According to the preset corresponding relationship table, the preset parameters corresponding to the valve failure are determined to be the valve opening of the hot primary air regulating valve and the valve opening of the cold primary air regulating valve of the coal mill;

[0254] The judgment module includes:

[0255] a third determining submodule, configured to determine a flow adjustment coefficient of the hot primary air regulating valve and a flow adjustment coefficient of the cold primary air regulating valve according to the valve opening of the hot primary air regulating valve and the valve opening of the cold primary air regulating valve of the coal mill;

[0256] A first calculation submodule is configured to calculate a theoretical value of hot primary air flow and a theoretical value of cold primary air flow according to the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve;

[0257] A second calculation submodule is used to calculate a theoretical value of mixed primary air flow and a theoretical value of mixed primary air temperature according to the theoretical value of hot primary air flow and the theoretical value of cold primary air flow;

[0258] A third comparison submodule is configured to compare the theoretical value of the mixed primary air flow rate with the actual value of the mixed primary air flow rate, and to compare the theoretical value of the mixed primary air temperature with the actual value of the mixed primary air temperature;

[0259] The third judgment submodule is used to judge whether the primary air system is abnormal according to the comparison result.

[0260] In one embodiment, the first calculation submodule is configured to:

[0261] Substitute the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve into the following primary air flow prediction model to determine the theoretical value of the hot primary air flow and the theoretical value of the cold primary air flow:

[0262]

[0263] Among them, Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of cold primary air flow; C v h C is the flow coefficient of the hot primary air adjustment valve; v c P is the flow coefficient of the cold primary air adjustment valve; h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; P mix is the pressure of the mixed primary air; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0264] The second calculation submodule is configured to:

[0265] Substitute the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate into the following formula to determine the theoretical value of the mixed primary air flow rate and the theoretical value of the mixed primary air temperature:

[0266] Q mix =Q h +Q C ;

[0267]

[0268] Among them, Q mix is the theoretical value of mixed primary air flow; Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of the cold primary air flow rate; T mix is the theoretical value of mixed primary air temperature; P h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; T h is the hot primary air inlet temperature; T c is the cold primary air inlet temperature; ρ h is the hot primary air density; ρ c is the density of cold primary air.

[0269] In one embodiment, the third comparison submodule is used to:

[0270] Determine the ratio of the deviation between the theoretical value of the mixed primary air flow and the actual value of the mixed primary air flow to the theoretical value of the mixed primary air flow as a first comparison result;

[0271] Determining a deviation between the theoretical value of the mixed primary air temperature and the actual value of the mixed primary air temperature as a second comparison result;

[0272] The third judgment submodule is further configured to:

[0273] When the first comparison result is greater than a preset proportional coefficient or the second comparison result is greater than a preset temperature deviation value, it is determined that the primary air system is abnormal.

[0274] In one embodiment, when the abnormality type is valve jamming, the determining module is configured to:

[0275] According to the preset corresponding relationship table, the preset parameters corresponding to the valve jam are determined to be the valve opening command value and the valve opening actual value of the coal mill primary air regulating valve;

[0276] The judgment module includes:

[0277] a third calculation submodule, configured to calculate a variance between a valve opening command value and a valve opening actual value of the primary air regulating valve according to a parameter value of the preset parameter;

[0278] The fourth determining submodule is configured to determine that the primary air system is abnormal when a variance between the valve opening command value and the valve opening actual value of the primary air regulating valve is greater than a preset variance threshold.

[0279] Figure 3 FIG. 1 is a schematic diagram of the hardware structure of a safety alarm system for a primary air system of a coal mill in one embodiment of the present application. Figure 3 As shown, the coal mill primary air system safety alarm system includes:

[0280] at least one processor 320; and,

[0281] A memory 304 in communication with the at least one processor 320; wherein,

[0282] The memory 304 stores instructions that can be executed by the at least one processor 320. The instructions are executed by the at least one processor 320 to implement the coal mill primary air system safety alarm method described in any of the above embodiments.

[0283] Reference Figure 3The coal mill primary air system safety alarm system 300 may include one or more of the following components: a processing component 302, a memory 304, a power supply component 306, a multimedia component 308, an audio component 310, an input / output (I / O) interface 312, a sensor component 314, and a communication component 316.

[0284] Processing component 302 generally controls the overall operation of coal mill primary air system safety alarm system 300. Processing component 302 may include one or more processors 320 to execute instructions to perform all or part of the steps of the aforementioned method. Furthermore, processing component 302 may include one or more modules to facilitate interaction between processing component 302 and other components. For example, processing component 302 may include a multimedia module to facilitate interaction between multimedia component 308 and processing component 302.

[0285] The memory 304 is configured to store various types of data to support the operation of the coal mill primary air system safety alarm system 300. Examples of such data include instructions for any application or method operating on the coal mill primary air system safety alarm system 300, such as text, images, videos, etc. The memory 304 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk, or optical disk.

[0286] The power supply assembly 306 provides power to various components of the coal mill primary air system safety alarm system 300. The power supply assembly 306 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power to the coal mill primary air system safety alarm system 300.

[0287] The multimedia component 308 includes a screen that provides an output interface between the coal mill primary air system safety alarm system 300 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touches, slides, and gestures on the touch panel. The touch sensor can not only sense the boundaries of the touch or slide action, but also detect the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 308 may also include a front camera and / or a rear camera. When the coal mill primary air system safety alarm system 300 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera can receive external multimedia data. Each front camera and rear camera can be a fixed optical lens system or have focal length and optical zoom capabilities.

[0288] The audio component 310 is configured to output and / or input audio signals. For example, the audio component 310 includes a microphone (MIC) that is configured to receive external audio signals when the coal mill primary air system safety alarm system 300 is in an operating mode, such as an alarm mode, a recording mode, a voice recognition mode, and a voice output mode. The received audio signals may be further stored in the memory 304 or transmitted via the communication component 316. In some embodiments, the audio component 310 also includes a speaker for outputting audio signals.

[0289] I / O interface 312 provides an interface between processing component 302 and peripheral interface modules, such as a keyboard, click wheel, buttons, etc. These buttons may include but are not limited to: a home button, volume buttons, a start button, and a lock button.

[0290] The sensor assembly 314 includes one or more sensors for providing various aspects of status assessment for the coal mill primary air system safety alarm system 300. For example, the sensor assembly 314 may include an acoustic sensor. In addition, the sensor assembly 314 may detect the on / off status of the coal mill primary air system safety alarm system 300, the relative positioning of components, such as the display and keypad of the coal mill primary air system safety alarm system 300, and the operating status of the coal mill primary air system safety alarm system 300 or a component of the coal mill primary air system safety alarm system 300. The sensor assembly 314 may include a proximity sensor configured to detect the presence of nearby objects without any physical contact. The sensor assembly 314 may also include an optical sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 314 may also include a magnetic sensor, a pressure sensor, a material stack thickness sensor, or a temperature sensor.

[0291] The communication component 316 is configured to enable the coal mill primary air system safety alarm system 300 to provide the ability to communicate with other devices and cloud platforms in a wired or wireless manner. The coal mill primary air system safety alarm system 300 can access a wireless network based on a communication standard, such as WiFi, 2G or 3G, or a combination thereof. In an exemplary embodiment, the communication component 316 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 316 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

[0292] In an exemplary embodiment, the coal mill primary air system safety alarm system 300 can be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors or other electronic components to execute the coal mill primary air system safety alarm method described in any of the above embodiments.

[0293] The present application also provides a computer-readable storage medium. When the instructions in the storage medium are executed by the processor corresponding to the coal mill primary air system safety alarm system, the coal mill primary air system safety alarm system can implement the coal mill primary air system safety alarm method recorded in any of the above embodiments.

[0294] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage and optical storage, etc.) that contain computer-usable program code.

[0295] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0296] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0297] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0298] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A coal mill primary air system safety alarm method, characterized in that: include: Obtaining the primary air system abnormality type that causes coal powder spontaneous combustion in the coal mill, wherein the abnormality type at least includes abnormal air temperature, abnormal temperature rise rate, valve failure, and valve jamming; Determine corresponding preset parameters according to the abnormality type; Determining whether the primary air system is abnormal according to the parameter value of the preset parameter; When an abnormality occurs in the primary air system, an alarm message is issued indicating that there is a risk of spontaneous combustion of coal powder in the pulverizer.

2. The method according to claim 1, wherein When the abnormality type is abnormal wind temperature, the determining of the corresponding preset parameters according to the abnormality type includes: According to the preset corresponding relationship table, the preset parameter corresponding to the abnormal wind temperature is determined to be the volatile matter content of the pulverized coal; The determining whether the primary air system is abnormal according to the parameter value of the preset parameter includes: determining the primary air explosion temperature of the coal mill according to the volatile matter content of the coal powder; Comparing the primary air inlet temperature of the coal mill with the primary air explosion temperature of the coal mill; Determine whether the primary air system is abnormal based on the comparison results.

3. The method according to claim 1, wherein When the abnormality type is a temperature rise rate abnormality, determining the corresponding preset parameters according to the abnormality type includes: According to the preset corresponding relationship table, the preset parameter corresponding to the abnormal temperature rise rate is determined to be the volatile matter content of the pulverized coal; The determining whether the primary air system is abnormal according to the parameter value of the preset parameter includes: determining a maximum temperature rise rate of the primary air system according to the volatile matter content of the pulverized coal; comparing the primary air temperature rise rate of the coal mill with the maximum temperature rise rate of the primary air system; Determine whether the primary air system is abnormal based on the comparison results.

4. The method according to claim 1, wherein When the abnormality type is valve failure, determining the corresponding preset parameters according to the abnormality type includes: According to the preset corresponding relationship table, the preset parameters corresponding to the valve failure are determined to be the valve opening of the hot primary air regulating valve and the valve opening of the cold primary air regulating valve of the coal mill; The determining whether the primary air system is abnormal according to the parameter value of the preset parameter includes: Determining a flow adjustment coefficient of the hot primary air adjustment valve and a flow adjustment coefficient of the cold primary air adjustment valve according to the valve opening of the hot primary air adjustment valve and the valve opening of the cold primary air adjustment valve of the coal mill; Calculating a theoretical value of hot primary air flow and a theoretical value of cold primary air flow according to the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve; Calculate the theoretical value of mixed primary air flow rate and the theoretical value of mixed primary air temperature according to the theoretical value of hot primary air flow rate and the theoretical value of cold primary air flow rate; Comparing the theoretical value of the mixed primary air flow rate with the actual value of the mixed primary air flow rate, and comparing the theoretical value of the mixed primary air temperature with the actual value of the mixed primary air temperature; Determine whether the primary air system is abnormal based on the comparison results.

5. The method according to claim 4, wherein The calculating of the hot primary air flow theoretical value and the cold primary air flow theoretical value according to the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve includes: Substitute the flow adjustment coefficient of the hot primary air adjustment valve and the flow adjustment coefficient of the cold primary air adjustment valve into the following primary air flow prediction model to determine the theoretical value of the hot primary air flow and the theoretical value of the cold primary air flow: Among them, Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of cold primary air flow; C v h C is the flow coefficient of the hot primary air adjustment valve; v c P is the flow coefficient of the cold primary air adjustment valve; h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; P mix is the pressure of the mixed primary air; ρ h is the hot primary air density; ρ c is the density of cold primary air. The calculating of the mixed primary air flow theoretical value and the mixed primary air temperature theoretical value according to the hot primary air flow theoretical value and the cold primary air flow theoretical value comprises: Substitute the theoretical value of the hot primary air flow rate and the theoretical value of the cold primary air flow rate into the following formula to determine the theoretical value of the mixed primary air flow rate and the theoretical value of the mixed primary air temperature: Among them, Q mix is the theoretical value of mixed primary air flow; Q h is the theoretical value of hot primary air flow; Q c is the theoretical value of the cold primary air flow rate; T mix is the theoretical value of mixed primary air temperature; P h is the hot primary air inlet pressure; P c is the cold primary air inlet pressure; T h is the hot primary air inlet temperature; T c is the cold primary air inlet temperature; ρh is the hot primary air density; ρ c is the density of cold primary air.

6. The method according to claim 4, wherein The comparing the theoretical value of the mixed primary air flow rate with the actual value of the mixed primary air flow rate, and the comparing the theoretical value of the mixed primary air temperature with the actual value of the mixed primary air temperature, includes: Determine the ratio of the deviation between the theoretical value of the mixed primary air flow and the actual value of the mixed primary air flow to the theoretical value of the mixed primary air flow as a first comparison result; Determining a deviation between the theoretical value of the mixed primary air temperature and the actual value of the mixed primary air temperature as a second comparison result; The determining whether the primary air system is abnormal according to the comparison result includes: When the first comparison result is greater than a preset proportional coefficient or the second comparison result is greater than a preset temperature deviation value, it is determined that the primary air system is abnormal.

7. The method according to claim 1, wherein When the abnormality type is a stuck valve, determining corresponding preset parameters according to the abnormality type includes: According to the preset corresponding relationship table, the preset parameters corresponding to the valve jam are determined to be the valve opening command value and the valve opening actual value of the coal mill primary air regulating valve; The determining whether the primary air system is abnormal according to the parameter value of the preset parameter includes: Calculating the variance between the valve opening command value and the valve opening actual value of the primary air regulating valve according to the parameter value of the preset parameter; When the variance between the valve opening command value and the valve opening actual measurement value of the primary air regulating valve is greater than a preset variance threshold, it is determined that the primary air system is abnormal.

8. A safety alarm device for the primary air system of a coal mill, characterized in that: include: an acquisition module, configured to acquire a primary air system abnormality type that causes spontaneous combustion of pulverized coal in a coal mill, wherein the abnormality type includes at least one of abnormal air temperature, abnormal temperature rise rate, valve failure, and valve jamming; A determination module, configured to determine corresponding preset parameters according to the abnormality type; a judgment module, configured to judge whether the primary air system is abnormal according to the parameter value of the preset parameter; The alarm module is used to issue an alarm message that the coal powder in the pulverizer has a risk of spontaneous combustion when an abnormality occurs in the primary air system.

9. A coal mill primary air system safety alarm system, characterized in that: include: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to implement the coal mill primary air system safety alarm method according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that When the instructions in the storage medium are executed by the processor corresponding to the coal mill primary air system safety alarm system, the coal mill primary air system safety alarm system can implement the coal mill primary air system safety alarm method according to any one of claims 1 to 7.

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