An energy-saving coal mill automatic control system

Abstract

The present invention relates to the technical field of energy-saving coal mills, and in particular to an automatic control system for energy-saving coal mills, comprising: a coal powder processing module for processing raw coal into coal powder through an energy-saving coal mill; a detection module, comprising a pressure sensor arranged inside the energy-saving coal mill for detecting the working pressure inside the energy-saving coal mill and a temperature sensor arranged inside the energy-saving coal mill for detecting the temperature inside the energy-saving coal mill; a communication module for transmitting the detected sensor data to a control module; the control module is respectively connected to the coal powder processing module, the detection module and the communication module, and is used to determine the preload of the electric valve according to the variance of the response time of the electric valve or determine the working pressure inside the energy-saving coal mill according to the average delay time of the operation of the energy-saving coal mill. The present invention improves the control stability of the energy-saving coal mill.

Description

Technical Field

[0001] The invention relates to the technical field of energy-saving coal mills, and in particular to an automatic control system for energy-saving coal mills. Background Art

[0002] In the prior art, a coal mill is a machine that breaks up coal blocks and grinds them into coal powder. It is an important auxiliary equipment for pulverized coal furnaces. Its task is to crush coal into suitable particle sizes for combustion in boilers. The performance of the coal mill has a vital impact on the efficiency and reliability of the entire production process. Therefore, the effectiveness and stability of the coal mill control system are crucial to maintaining the continuity and quality of power production.

[0003] Chinese Patent Publication No.: CN118287244A discloses a coal mill intelligent adjustment control system and method, the system includes: a monitoring module, used to set the characteristic components of the coal mill according to the historical vibration parameter set, and establish multiple monitoring sub-areas according to the characteristic components; a construction module, used to construct a vibration-state evaluation model, and generate a state evaluation value of each monitoring sub-area according to the vibration-state prediction model; a prediction module, used to set the monitoring time node of the corresponding monitoring sub-area according to the state evaluation value, collect the real-time vibration parameters of the corresponding components according to the monitoring time node and generate the abnormal probability of the corresponding monitoring sub-area; an adjustment module, used to determine the comprehensive operation state of the coal mill according to the abnormal probability of each monitoring sub-area, generate an adjustment instruction according to the comprehensive operation state, and determine whether to send an alarm signal. It can be seen that the coal mill intelligent adjustment control system and method have the problem that the internal parts of the coal mill are poorly lubricated due to the long use time of the coal mill, which leads to increased friction during valve operation, hinders the movement of moving parts, and thus causes the control stability of the energy-saving coal mill to decrease. Summary of the invention

[0004] To this end, the present invention provides an energy-saving coal mill automatic control system to overcome the problem in the prior art that the internal parts of the coal mill are poorly lubricated due to the long use time, which leads to increased friction during valve operation, hindering the movement of moving parts and thus causing a decrease in the control stability of the energy-saving coal mill.

[0005] To achieve the above-mentioned purpose, the present invention provides an energy-saving coal mill automatic control system, comprising: a coal powder processing module, used for processing raw coal into coal powder through an energy-saving coal mill, comprising a feeding unit for conveying the raw coal, a grinding unit connected to the feeding unit for grinding the raw coal, a cooling unit connected to the grinding unit for cooling the grinding unit, and a discharging unit connected to the grinding unit for outputting the coal powder; wherein the feeding unit comprises an electric valve for controlling the supply rate of raw coal and the flow rate of combustion air, and the cooling unit comprises a coolant pump for controlling the delivery rate of coolant; a detection module, which is connected to the coal powder processing module, and is arranged in the energy-saving coal mill. a pressure sensor for detecting the working pressure inside the energy-saving coal mill and a temperature sensor for detecting the temperature inside the energy-saving coal mill; a communication module connected to the detection module, for transmitting the detected sensor data to the control module; the control module, which is respectively connected to the coal powder processing module, the detection module and the communication module, for determining the preload force of the electric valve according to the variance of the response time of the electric valve or determining the working pressure inside the energy-saving coal mill according to the average delay time of the operation of the energy-saving coal mill, and determining the speed of the coolant pump according to the average delay time of the operation of the energy-saving coal mill and the temperature rise rate inside the energy-saving coal mill.

[0006] Furthermore, the control module is used to determine whether the control stability of the energy-saving coal mill meets the requirements based on the variance of the response time of the electric valve. If the variance of the response time of the electric valve is greater than a preset first variance, it is determined that the control stability of the energy-saving coal mill does not meet the requirements.

[0007] Furthermore, the control module is used to preliminarily determine that the control reliability of the energy-saving coal mill does not meet the requirements when the variance of the response time of the electric valve is greater than the preset first variance and less than or equal to the preset second variance, and determine whether the control reliability of the energy-saving coal mill meets the requirements based on the average delay time of the energy-saving coal mill operation.

[0008] Further, the control module is used to reduce the preload force of the electric valve when the variance of the response time of the electric valve is greater than the preset second variance;

[0009] The reduction range of the preload force of the electric valve is determined by the difference between the variance of the response time of the electric valve and a preset second variance.

[0010] Furthermore, the control module is used to determine whether the control reliability of the energy-saving coal mill meets the requirements based on the average delay time of the energy-saving coal mill operation. If the average delay time of the energy-saving coal mill operation is greater than the preset first delay time, it is determined that the control reliability of the energy-saving coal mill does not meet the requirements.

[0011] Furthermore, the control module is used to preliminarily determine that the environmental stability of the energy-saving coal mill does not meet the requirements when the average delay time of the energy-saving coal mill operation is greater than a preset second delay time, and determine whether the environmental stability of the energy-saving coal mill meets the requirements based on the temperature rise rate inside the energy-saving coal mill.

[0012] Furthermore, the control module is used to reduce the working pressure inside the energy-saving coal mill when the average delay time of the energy-saving coal mill operation is greater than the preset first delay time and less than or equal to the preset second delay time.

[0013] Furthermore, the reduction range of the working pressure inside the energy-saving coal mill is determined by the difference between the average delay time of the energy-saving coal mill operation and the preset first delay time.

[0014] Furthermore, the control module is used to determine whether the environmental stability of the energy-saving coal mill meets the requirements based on the temperature rise rate inside the energy-saving coal mill. If the temperature rise rate inside the energy-saving coal mill is greater than the preset rise rate, it is determined that the environmental stability of the energy-saving coal mill does not meet the requirements, and the speed of the coolant pump is increased.

[0015] Furthermore, the increase range of the rotation speed of the coolant pump is determined by the difference between the temperature increase rate inside the energy-saving coal mill and a preset increase rate.

[0016] Compared with the prior art, the beneficial effect of the present invention lies in that the system of the present invention determines the preload force of the electric valve according to the variance of the response time of the electric valve by setting a coal powder processing module, a detection module, a communication module and a control module. The internal parts of the coal mill are poorly lubricated due to the long use time of the coal mill, which increases the friction when the valve is running, hinders the rapid movement of the moving parts and affects the response speed. By reducing the preload force of the electric valve, the resistance that needs to be overcome when the valve is opened and closed is reduced, which helps to reduce the resistance of friction to the movement of the valve to a certain extent, so that the valve can be moved relatively more easily, thereby improving the response speed. The working pressure inside the energy-saving coal mill is determined according to the average delay time of the energy-saving coal mill. Due to the aging of the skin of the communication cable, the cable in some positions is exposed to the outside, resulting in poor contact, resulting in Signal transmission is blocked, resulting in delays. By reducing the working pressure inside the energy-saving coal mill, the intensity of equipment operation can be reduced, the demand for real-time response of the control system can be reduced, and the adverse effects caused by communication delays can be alleviated to a certain extent, so that the coal mill can operate relatively safely when the communication is not stable. The speed of the coolant pump is determined according to the temperature rise rate inside the energy-saving coal mill. Since the coal mill will generate a lot of heat during operation, and the coolant may be mixed with impurities or oil during long-term use, the cooling performance of the coolant will be reduced, causing some cooling pipes to be blocked, affecting the normal operation of the cooling system. By increasing the speed of the coolant pump, the flow rate of the coolant can be increased, so that more coolant can circulate in the system, reducing the blockage of the cooling pipes, thereby enhancing the cooling effect and improving the control stability of the energy-saving coal mill.

[0017] Furthermore, the system of the present invention determines the preload force of the electric valve by setting a preset first variance and a preset second variance. Since the coal mill has been in use for too long, the lubrication of internal components is poor, which leads to increased friction during valve operation, hindering the rapid movement of moving parts and affecting the response speed. By reducing the preload force of the electric valve, the resistance that needs to be overcome when the valve is opened and closed is reduced, which helps to reduce the resistance of friction to valve movement to a certain extent, allowing the valve to move relatively more easily, thereby improving the response speed and further improving the control stability of the energy-saving coal mill.

[0018] Furthermore, the system of the present invention determines the working pressure inside the energy-saving coal mill by setting a preset first delay time and a preset second delay time. Due to the aging of the surface of the communication cable, the cable in some positions is exposed to the outside, resulting in poor contact, which causes the signal transmission to be blocked, thereby causing delays. By reducing the working pressure inside the energy-saving coal mill, the intensity of equipment operation can be reduced, and the demand for real-time response of the control system can be reduced. To a certain extent, the adverse effects caused by communication delays can be alleviated, so that the coal mill can operate relatively safely when the communication is not stable, further improving the control stability of the energy-saving coal mill.

[0019] Furthermore, the system of the present invention determines the rotation speed of the coolant pump by setting a preset increase rate. Since the coal mill generates a large amount of heat during operation, and the coolant may be mixed with impurities or oil during long-term use, the cooling performance of the coolant will be reduced, causing some cooling pipes to be blocked, affecting the normal operation of the cooling system. By increasing the rotation speed of the coolant pump, the flow rate of the coolant can be increased, so that more coolant can circulate in the system, reducing the blockage of the cooling pipes, thereby enhancing the cooling effect and further improving the control stability of the energy-saving coal mill. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is an overall structural block diagram of an energy-saving coal mill automation control system according to an embodiment of the present invention;

[0021] Figure 2 It is a logic flow chart of the energy-saving coal mill automation control system according to an embodiment of the present invention;

[0022] Figure 3 It is a specific structural block diagram of the coal powder processing module of the energy-saving coal mill automatic control system according to an embodiment of the present invention;

[0023] Figure 4 It is a specific structural block diagram of the detection module of the energy-saving coal mill automatic control system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0025] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0026] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0027] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] See also Figure 1 , Figure 2 , Figure 3 as well as Figure 4 As shown, they are respectively the overall structure block diagram of the energy-saving coal mill automation control system of the embodiment of the present invention, the logic flow chart, the specific structure block diagram of the coal powder processing module and the specific structure block diagram of the detection module. An energy-saving coal mill automation control system of the present invention includes:

[0029] A pulverized coal processing module, used for processing raw coal into pulverized coal through an energy-saving coal mill, comprising a feeding unit for conveying the raw coal, a grinding unit connected to the feeding unit for grinding the raw coal, a cooling unit connected to the grinding unit for cooling the grinding unit, and a discharging unit connected to the grinding unit for discharging the pulverized coal;

[0030] Wherein, the feeding unit includes an electric valve for controlling the supply rate of raw coal and the flow rate of combustion air, and the cooling unit includes a coolant pump for controlling the delivery rate of coolant;

[0031] a detection module connected to the pulverized coal processing module, comprising a pressure sensor disposed inside the energy-saving coal mill for detecting the working pressure inside the energy-saving coal mill and a temperature sensor disposed inside the energy-saving coal mill for detecting the temperature inside the energy-saving coal mill;

[0032] a communication module, connected to the detection module, for transmitting the detected sensor data to the control module;

[0033] The control module is respectively connected to the coal powder processing module, the detection module and the communication module, and is used to determine the preload force of the electric valve according to the variance of the response time of the electric valve or determine the working pressure inside the energy-saving coal mill according to the average delay time of the energy-saving coal mill operation, and determine the speed of the coolant pump according to the average delay time of the energy-saving coal mill operation and the temperature rise rate inside the energy-saving coal mill.

[0034] Specifically, the feeding unit also includes:

[0035] A feed hopper, which is arranged above the electric valve and is used to store raw coal;

[0036] A feeding pipeline is connected to the feeding hopper and is used for conveying raw coal into the coal mill.

[0037] Specifically, the grinding unit includes:

[0038] A grinding disc, which is arranged inside the coal mill and is used to provide a grinding platform for raw coal;

[0039] The grinding roller is connected to the grinding disc and is used for extruding and grinding the raw coal on the grinding disc.

[0040] Specifically, the cooling unit also includes:

[0041] A coolant storage tank, used to store coolant;

[0042] A delivery pipeline is connected to the coolant storage tank and is used to deliver the coolant.

[0043] Specifically, the discharging unit includes:

[0044] a discharge pipe connected to the coal mill for conveying coal powder;

[0045] A pulverized coal bin is arranged at the output end of the discharge pipe and is used to collect the pulverized coal.

[0046] Specifically, the detection module also includes:

[0047] A vibration sensor connected to the coal mill to detect the vibration intensity of the coal mill during operation;

[0048] A current sensor is connected to the coal mill and is used to detect the working current of the motor in the coal mill.

[0049] Specifically, the preload force of the electric valve is the force applied to the valve seal to ensure the sealing of the valve when the electric valve is closed. It is operated by a drive motor connected to the electric valve, and the rotational motion is converted into linear motion through a reducer and a transmission mechanism, thereby pushing the valve core to move, thereby realizing the adjustment of the preload force of the electric valve.

[0050] Specifically, the working pressure inside the energy-saving coal mill is reduced by increasing the air supply volume inside the energy-saving coal mill.

[0051] In implementation, the system of the present invention determines the preload force of the electric valve according to the variance of the response time of the electric valve by setting a coal powder processing module, a detection module, a communication module and a control module. The internal parts of the coal mill are poorly lubricated due to the long use time of the coal mill, which increases the friction when the valve is running, hinders the rapid movement of the moving parts and affects the response speed. By reducing the preload force of the electric valve, the resistance that needs to be overcome when the valve is opened and closed is reduced, which helps to reduce the resistance of friction to the movement of the valve to a certain extent, so that the valve can move relatively more easily, thereby improving the response speed. The working pressure inside the energy-saving coal mill is determined according to the average delay time of the energy-saving coal mill. Due to the aging of the skin of the communication cable, the cable in some positions is exposed to the outside, resulting in poor contact, which leads to obstruction of signal transmission. This will cause a delay. By reducing the working pressure inside the energy-saving coal mill, the intensity of equipment operation can be reduced, the demand for real-time response of the control system can be reduced, and the adverse effects caused by communication delays can be alleviated to a certain extent, so that the coal mill can operate relatively safely when the communication is not stable. The speed of the coolant pump is determined according to the temperature rise rate inside the energy-saving coal mill. Since the coal mill will generate a lot of heat during operation, and the coolant may be mixed with impurities or oil during long-term use, the cooling performance of the coolant will be reduced, causing some cooling pipes to be blocked, affecting the normal operation of the cooling system. By increasing the speed of the coolant pump, the flow rate of the coolant can be increased, so that more coolant can circulate in the system, reducing the blockage of the cooling pipes, thereby enhancing the cooling effect and improving the control stability of the energy-saving coal mill.

[0052] Specifically, the control module is used to obtain the response time of the electric valve within several control cycles and calculate the variance of the response time of the electric valve. If the variance of the response time of the electric valve is greater than a preset first variance, it is determined that the control stability of the energy-saving coal mill does not meet the requirements.

[0053] Specifically, the control module is used to preliminarily determine that the control reliability of the energy-saving coal mill does not meet the requirements when the variance of the response time of the electric valve is greater than the preset first variance and less than or equal to the preset second variance, and determine whether the control reliability of the energy-saving coal mill meets the requirements based on the average delay time of the energy-saving coal mill operation.

[0054] It can be understood that the three intervals corresponding to the preset first variance and the preset second variance correspond to three situations respectively:

[0055] The first interval is when the variance of the response time of the electric valve is less than or equal to the preset first variance, corresponding to the situation where the control stability of the energy-saving coal mill meets the requirements;

[0056] The second interval is when the variance of the response time of the electric valve is greater than the preset first variance and less than or equal to the preset second variance, corresponding to the aging of the surface of the communication cable, resulting in partial exposure of the cable to the outside, poor contact, and obstruction of signal transmission, thereby causing a delay;

[0057] The third interval is when the variance of the response time of the electric valve is greater than the preset second variance. This corresponds to the situation where the coal mill has been in use for too long, resulting in poor lubrication of internal components, increased friction during valve operation, hindering the rapid movement of moving parts and affecting the response speed.

[0058] In practice, the range of the preset first variance is generally selected as [1.2s 2 , 1.4s 2 ], the default second variance is generally selected in the range of [1.4s 2 , 1.6s 2 ].

[0059] Preferably, the preferred embodiment of the preset first variance is 1.3s 2 The preferred embodiment of the preset second variance is 1.5s 2 .

[0060] Specifically, the variance of the response time of the electric valve is the variance of the response time of the electric valve within several control cycles. The calculation method of the variance of the response time of the electric valve is a conventional technical means well known to technical personnel in this field. Therefore, the calculation process of the variance of the response time of the electric valve will not be repeated here.

[0061] In implementation, the system of the present invention determines the control stability of the energy-saving coal mill by setting a preset first variance and a preset second variance, thereby reducing the impact of the reduction in control accuracy of the energy-saving coal mill due to inaccurate determination of the control stability of the energy-saving coal mill, and further improving the control stability of the energy-saving coal mill.

[0062] Specifically, the control module is used to reduce the preload force of the electric valve when the variance of the response time of the electric valve is greater than the preset second variance;

[0063] The reduction range of the preload force of the electric valve is determined by the difference between the variance of the response time of the electric valve and a preset second variance.

[0064] Specifically, the difference between the variance of the response time of the electric valve and the preset second variance is 0.2s. 2When the difference between the variance of the response time of the electric valve and the preset second variance exceeds 0.2s, the preload force of the electric valve is reduced to 0.95 times of the original value. 2 When the time exceeds 0.1s 2 , the preload force of the electric valve is reduced by 25N. For example, the difference between the variance of the response time of the electric valve and the preset second variance is 0.5s 2 , the current preload force of the electric valve is 500N, and the reduced preload force of the electric valve is 500×0.95-25×3=400N.

[0065] In implementation, the system of the present invention determines the preload force of the electric valve by setting a preset first variance and a preset second variance. Since the coal mill has been in use for too long, the lubrication of the internal components is poor, which leads to increased friction during valve operation, hindering the rapid movement of the moving parts and affecting the response speed. By reducing the preload force of the electric valve, the resistance that needs to be overcome when the valve is opened and closed is reduced, which helps to reduce the resistance of friction to the movement of the valve to a certain extent, allowing the valve to move relatively more easily, thereby improving the response speed and further improving the control stability of the energy-saving coal mill.

[0066] Specifically, the control module is used to obtain the delay time of the energy-saving coal mill operation within several operation cycles, and calculate the average delay time of the energy-saving coal mill operation. If the average delay time of the energy-saving coal mill operation is greater than the preset first delay time, it is determined that the control reliability of the energy-saving coal mill does not meet the requirements.

[0067] Specifically, the control module is used to preliminarily determine that the environmental stability of the energy-saving coal mill does not meet the requirements when the average delay time of the energy-saving coal mill is greater than the preset second delay time, and determine whether the environmental stability of the energy-saving coal mill meets the requirements based on the temperature rise rate inside the energy-saving coal mill.

[0068] It can be understood that the three intervals corresponding to the preset first delay duration and the preset second delay duration correspond to three situations respectively:

[0069] The first interval is when the average delay time of the energy-saving coal mill operation is less than or equal to the preset first delay time, corresponding to the situation where the reliability of the energy-saving coal mill meets the requirements;

[0070] The second interval is when the average delay time of the energy-saving coal mill is greater than the preset first delay time and less than or equal to the preset second delay time. The surface of the corresponding communication cable is aged, causing the cable in some positions to be exposed to the outside, resulting in poor contact, which leads to obstruction of signal transmission and thus delay.

[0071] The third interval is when the average delay time of the energy-saving coal mill is longer than the preset second delay time. The corresponding coal mill will generate a lot of heat during operation, and the coolant may be mixed with impurities or oil during long-term use, resulting in a decrease in the cooling performance of the coolant and blockage of some cooling pipes, affecting the normal operation of the cooling system.

[0072] In practice, the preset first delay time length is generally selected in the range of [420ms, 440ms], and the preset second delay time length is generally selected in the range of [440ms, 460ms].

[0073] Preferably, the preferred embodiment of the preset first delay time length is 430ms, and the preferred embodiment of the preset second delay time length is 450ms.

[0074] Specifically, the average delay time of the energy-saving coal mill operation is the ratio of the total delay time of the energy-saving coal mill operation in several operation cycles to the number of operation cycles.

[0075] In implementation, the system of the present invention determines the control reliability of the energy-saving coal mill by setting a preset first delay time and a preset second delay time, thereby reducing the impact of the decreased control stability of the energy-saving coal mill due to inaccurate determination of the control reliability of the energy-saving coal mill, and further improving the control stability of the energy-saving coal mill.

[0076] Specifically, the control module is used to reduce the working pressure inside the energy-saving coal mill when the average delay time of the energy-saving coal mill operation is greater than the preset first delay time and less than or equal to the preset second delay time.

[0077] Specifically, the reduction range of the working pressure inside the energy-saving coal mill is determined by the difference between the average delay time of the energy-saving coal mill operation and the preset first delay time.

[0078] Specifically, when the difference between the average delay time of the energy-saving coal mill and the preset first delay time is within 30ms, the working pressure inside the energy-saving coal mill is reduced to 0.9 times the original pressure; when the difference between the average delay time of the energy-saving coal mill and the preset first delay time exceeds 30ms, the working pressure inside the energy-saving coal mill is reduced by 2kPa for every 10ms exceeding the original pressure. For example, the difference between the average delay time of the energy-saving coal mill and the preset first delay time is 50ms. The current working pressure inside the energy-saving coal mill is 28kPa, and the reduced working pressure inside the energy-saving coal mill is 28×0.9-2×2=21.2kPa.

[0079] In implementation, the system of the present invention determines the working pressure inside the energy-saving coal mill by setting a preset first delay time and a preset second delay time. Due to the aging of the surface of the communication cable, the cable in some positions is exposed to the outside, resulting in poor contact, which causes the signal transmission to be blocked, thereby causing delays. By reducing the working pressure inside the energy-saving coal mill, the intensity of equipment operation can be reduced, and the demand for real-time response of the control system can be reduced. To a certain extent, the adverse effects caused by communication delays can be alleviated, so that the coal mill can operate relatively safely when the communication is not stable, further improving the control stability of the energy-saving coal mill.

[0080] Specifically, the control module is used to obtain the temperature inside the energy-saving coal mill at the initial moment of a single operating cycle and the temperature inside the energy-saving coal mill at the end moment of a single operating cycle, and calculate the temperature increase rate inside the energy-saving coal mill. If the temperature increase rate inside the energy-saving coal mill is greater than the preset increase rate, it is determined that the environmental stability of the energy-saving coal mill does not meet the requirements, and the speed of the coolant pump is increased.

[0081] It can be understood that the two intervals corresponding to the preset increase rate correspond to two situations:

[0082] The first interval is when the temperature increase rate inside the energy-saving coal mill is less than or equal to the preset increase rate, corresponding to the situation where the environmental stability of the energy-saving coal mill meets the requirements;

[0083] The second interval is when the temperature rise rate inside the energy-saving coal mill is greater than the preset rise rate. The corresponding coal mill will generate a large amount of heat during operation, and the coolant may be mixed with impurities or oil during long-term use, resulting in a decrease in the cooling performance of the coolant and blockage of some cooling pipes, affecting the normal operation of the cooling system.

[0084] In practice, the preset temperature increase rate is generally selected in the range of [14°C / min, 16°C / min].

[0085] Preferably, the preset increasing rate is preferably 15° C. / min.

[0086] Specifically, the temperature rise rate inside the energy-saving coal mill is the ratio of the difference between the temperature inside the energy-saving coal mill at the end of a single operating cycle and the temperature inside the energy-saving coal mill at the initial moment of a single operating cycle to the duration of a single operating cycle.

[0087] During implementation, the system of the present invention determines the environmental stability of the energy-saving coal mill by setting a preset increase rate, thereby reducing the impact of the decreased control stability of the energy-saving coal mill due to inaccurate determination of the environmental stability of the energy-saving coal mill, and further improving the control stability of the energy-saving coal mill.

[0088] Specifically, the increase range of the rotation speed of the coolant pump is determined by the difference between the temperature increase rate inside the energy-saving coal mill and the preset increase rate.

[0089] Specifically, when the difference between the temperature rise rate inside the energy-saving coal mill and the preset temperature rise rate is within 3°C / min, the speed of the coolant pump increases to 1.1 times the original speed; when the difference between the temperature rise rate inside the energy-saving coal mill and the preset temperature rise rate exceeds 3°C / min, the speed of the coolant pump increases by 50r / min for every 2°C / min exceeding it. For example, the difference between the temperature rise rate inside the energy-saving coal mill and the preset temperature rise rate is 5°C / min, the current speed of the coolant pump is 1200r / min, and the increased speed of the coolant pump is 1200×1.1+50×2=1420r / min.

[0090] In implementation, the system of the present invention determines the rotation speed of the coolant pump by setting a preset increase rate. Since the coal mill generates a large amount of heat during operation, and the coolant may be mixed with impurities or oil during long-term use, the cooling performance of the coolant will be reduced, causing some cooling pipes to be blocked, affecting the normal operation of the cooling system. By increasing the rotation speed of the coolant pump, the flow rate of the coolant can be increased, so that more coolant can circulate in the system, reducing the blockage of the cooling pipes, thereby enhancing the cooling effect and further improving the control stability of the energy-saving coal mill.

[0091] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An energy-saving coal mill automatic control system, characterized in that: include: A pulverized coal processing module, used for processing raw coal into pulverized coal through an energy-saving coal mill, comprising a feeding unit for conveying the raw coal, a grinding unit connected to the feeding unit for grinding the raw coal, a cooling unit connected to the grinding unit for cooling the grinding unit, and a discharging unit connected to the grinding unit for discharging the pulverized coal; Wherein, the feeding unit includes an electric valve for controlling the supply rate of raw coal and the flow rate of combustion air, and the cooling unit includes a coolant pump for controlling the delivery rate of coolant; a detection module connected to the pulverized coal processing module, comprising a pressure sensor disposed inside the energy-saving coal mill for detecting the working pressure inside the energy-saving coal mill and a temperature sensor disposed inside the energy-saving coal mill for detecting the temperature inside the energy-saving coal mill; a communication module, connected to the detection module, for transmitting the detected sensor data to the control module; The control module is connected to the pulverized coal processing module, the detection module and the communication module respectively, and is used to determine the preload force of the electric valve according to the variance of the response time of the electric valve or determine the working pressure inside the energy-saving coal mill according to the average delay time of the energy-saving coal mill operation, and determine the speed of the coolant pump according to the average delay time of the energy-saving coal mill operation and the temperature rise rate inside the energy-saving coal mill; The control module is used to determine whether the control stability of the energy-saving coal mill meets the requirements according to the variance of the response time of the electric valve, and if the variance of the response time of the electric valve is greater than the preset first variance, it is determined that the control stability of the energy-saving coal mill does not meet the requirements; The control module is used to preliminarily determine that the control reliability of the energy-saving coal mill does not meet the requirements when the variance of the response time of the electric valve is greater than the preset first variance and less than or equal to the preset second variance, and determine whether the control reliability of the energy-saving coal mill meets the requirements according to the average delay time of the energy-saving coal mill operation; The control module is used for reducing the preload force of the electric valve when the variance of the response time length of the electric valve is greater than the preset second variance; The control module is used to determine whether the control reliability of the energy-saving coal mill meets the requirements according to the average delay time of the energy-saving coal mill operation. If the average delay time of the energy-saving coal mill operation is greater than the preset first delay time, it is determined that the control reliability of the energy-saving coal mill does not meet the requirements; The control module is used to preliminarily determine that the environmental stability of the energy-saving coal mill does not meet the requirements when the average delay time of the energy-saving coal mill is greater than the preset second delay time, and determine whether the environmental stability of the energy-saving coal mill meets the requirements according to the temperature increase rate inside the energy-saving coal mill; The control module is used to reduce the working pressure inside the energy-saving coal mill when the average delay time of the energy-saving coal mill operation is greater than the preset first delay time and less than or equal to the preset second delay time; The control module is used to determine whether the environmental stability of the energy-saving coal mill meets the requirements based on the temperature rise rate inside the energy-saving coal mill. If the temperature rise rate inside the energy-saving coal mill is greater than the preset rise rate, it is determined that the environmental stability of the energy-saving coal mill does not meet the requirements, and the speed of the coolant pump is increased.

2. The energy-saving coal mill automation control system according to claim 1 is characterized in that: The reduction range of the preload force of the electric valve is determined by the difference between the variance of the response time of the electric valve and a preset second variance.

3. The energy-saving coal mill automation control system according to claim 2 is characterized in that: The reduction range of the working pressure inside the energy-saving coal mill is determined by the difference between the average delay time of the energy-saving coal mill operation and the preset first delay time.

4. The energy-saving coal mill automation control system according to claim 3 is characterized in that: The increase range of the rotation speed of the coolant pump is determined by the difference between the temperature increase rate inside the energy-saving coal mill and the preset increase rate.

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