Multi-heat-source cooperative preheating mine air intake flow system and regulation method

Abstract

The application discloses a kind of multi-heat source coordination preheating mine air intake flow system and adjusting method, including air intake well roadway, air compressor waste heat recovery unit, ground temperature preheating unit, heater unit and temperature monitoring unit;Air intake well roadway entrance is provided with adjustable air window well mouth building;Air compressor waste heat recovery unit includes air compressor, pipeline connecting air compressor and air intake well roadway entrance, and waste heat fan is set in pipeline composition;Ground temperature preheating unit includes shallow goaf filled with waste rock, shallow waste well roadway connecting goaf and air intake well roadway, ground temperature preheating fan and ground temperature preheating damper are set in connecting place;Heater unit includes heating unit arranged on ground and pipeline connecting unit and air intake well roadway entrance composition;Temperature monitoring unit includes temperature sensor installed below well roadway connecting place and ground;Each unit is connected with air intake well roadway entrance by pipeline, and multi-heat source staged preheating is realized.The application realizes energy cascade utilization and cost optimization by constructing air compressor waste heat, ground temperature rock heat and multi-stage coordinated preheating system of heater unit.

Description

Technical Field

[0001] This invention belongs to the field of mine ventilation technology, specifically a multi-heat source synergistic preheating mine intake airflow system and its adjustment method. Background Technology

[0002] Mining operations require a continuous supply of fresh air for workers to breathe, for expelling stale air, and for regulating the underground climate. In cold and high-altitude regions, surface air temperatures are low in winter. When this low-temperature air enters the mine directly, it can easily cause the shaft to freeze, severely impacting the safe operation of equipment and threatening personnel safety. Furthermore, the low temperature environment is detrimental to underground operations, affecting worker health and reducing production efficiency. Article 6.6.1.5 of my country's "Safety Regulations for Metal and Non-metal Mines" (GB 16423-2020) stipulates that the air temperature in the intake shaft should not be lower than 2℃. Therefore, when the temperature of the airflow entering the mine is lower than 2℃, the intake air must be preheated.

[0003] Currently, there are two commonly used methods for preheating intake airflow: one is to preheat the intake air using shallow abandoned shafts and goaf areas, i.e., the geothermal preheating method; the other is to install a heater unit at the intake point to preheat the airflow, i.e., the heater preheating method. Both methods have certain drawbacks. The preheating capacity of the geothermal preheating method mainly depends on the quantity of available abandoned shafts and goaf areas and the temperature of the surrounding rock, which can easily limit its ability to preheat intake airflow. The heater preheating method requires the installation of a heater, which has high energy consumption and can easily lead to a significant increase in production costs.

[0004] In addition, without preheating the airflow, the temperature of the airflow entering the well is determined by the temperature of the surface air. The temperature of the surface air changes dynamically with time and season. Without considering the dynamic changes in the airflow temperature, it is difficult to accurately control the temperature of the preheated airflow, which can easily lead to energy waste or insufficient preheating temperature. Summary of the Invention

[0005] The main objective of this invention is to provide a multi-heat source synergistic preheating mine intake airflow system and its regulation method that significantly reduces overall energy consumption while maintaining good system stability.

[0006] The multi-heat-source synergistic preheating system for mine intake airflow provided by this invention includes an intake shaft, an air compressor waste heat recovery unit, a geothermal preheating unit, a heater unit, and a temperature monitoring unit. A shaft entrance structure with adjustable air vents is installed at the intake shaft entrance. The air compressor waste heat recovery unit comprises an air compressor, a pipeline connecting the air compressor to the intake shaft entrance, and a waste heat fan installed within the pipeline. The geothermal preheating unit comprises a shallow goaf filled with waste rock, a shallow abandoned shaft connecting the goaf and the intake shaft, a geothermal preheating fan installed at the connection point, and a geothermal preheating damper. The heater unit comprises a heating unit arranged on the ground and a pipeline connecting the unit to the intake shaft entrance. The temperature monitoring unit includes temperature sensors installed below the shaft connection point and on the ground. Each unit is synergistically connected to the intake shaft entrance via pipelines to achieve multi-heat-source staged preheating.

[0007] In one embodiment of the above system, the shallow abandoned shaft is formed by a combination of vertical shafts, inclined shafts, and horizontal shafts to create a ventilation channel.

[0008] In one embodiment of the above system, the heating unit in the heater unit adopts a frequency conversion controlled heating device.

[0009] In one embodiment of the above system, the shallow goaf of the geothermal preheating unit is connected to the surface through shallow abandoned shafts to form a cold air entry channel.

[0010] In one embodiment of the above system, the air compressor waste heat recovery unit includes multiple air compressors connected in parallel.

[0011] In one embodiment of the above system, the air compressor pipeline is an insulated pipeline.

[0012] In one embodiment of the above system, the heating unit is an air heater.

[0013] In one embodiment of the above system, a PLC automatic control system is configured, the hardware of which includes a ground industrial control computer, a PLC base station, a temperature sensor, an execution terminal, and an alarm; the ground industrial control computer serves as the control center; the PLC base station is connected and communicates with the ground industrial control computer; the temperature sensor is connected to the PLC base station; the execution terminal includes an air compressor waste heat fan, a ground temperature preheating damper, a ground temperature preheating fan, a heater unit, and a wellhead building regulating vent; each component of the execution terminal is independently connected in parallel with the PLC base station; the alarm is connected to the PLC base station.

[0014] A method for regulating a multi-heat source synergistic preheating mine intake airflow system using any one of the above methods, comprising the following specific steps:

[0015] S1. Perform temperature detection and set initial judgment;

[0016] The airflow temperature T is monitored in real time using a temperature sensor.

[0017] The PLC system is set to a target temperature threshold range of 2 to 5°C. When T < 2°C, the preheating system is triggered to start, and when T > 5°C, the heat source is triggered to shut down.

[0018] S2. When step S1 determines that the temperature is lower than the set value, the air compressor heat source is activated, and the air compressor heat source is determined.

[0019] When the airflow temperature T first drops below 2℃ and the air compressor is running, turn on the air compressor waste heat fan and transport the waste heat to the intake shaft entrance through the pipeline.

[0020] Calculate the heat supply Q1 from the waste heat of the air compressor and compare it with the heat requirement kQ0 for the preheated airflow in the mine;

[0021] The waste heat supplied by the air compressor, Q1, can be calculated using the following formula:

[0022]

[0023] In the formula: Q1 is the preheating heat of the air compressor waste heat, in kW;

[0024] η1 is the waste heat utilization coefficient of the air compressor, ranging from 0.6 to 0.8;

[0025] η2 is the load factor, representing the ratio of the average actual power consumption per hour to the maximum actual power consumption of the air compressor motor, ranging from 0.5 to 0.8.

[0026] η3 is the simultaneous use coefficient, which is the ratio of the installed power used simultaneously to the total installed power, and is generally 0.5 to 1.0.

[0027] N represents the rated installed power of the air compressor, in kW;

[0028] η is the efficiency of the air compressor motor, ranging from 0.85 to 0.95;

[0029] The heat required for preheating airflow in a mine, Q0, can be calculated using the following formula:

[0030] Q0 = 0.239Q b γC p (t2-t1)

[0031] In the formula: Q0 is the heat required for preheating airflow in the mine, in kW;

[0032] Q b This refers to the air intake volume of the intake shaft, expressed in cubic meters (m³). 3 / s;

[0033] γ is the weight percentage of cold air, in kg / m³. 3 ;

[0034] C p This is the specific heat of air at constant pressure, expressed in kcal / (kg℃).

[0035] t1 is the temperature of the cold air at ground level, in °C;

[0036] t2 is the temperature of the air after preheating, in units of 2.0℃.

[0037] Compare Q1 with kQ0, where k is the heat reserve coefficient for the preheated airflow, ranging from 1.1 to 1.3;

[0038] If Q1 is greater than kQ0, and T is greater than 5℃, then the waste heat fan of the air compressor should be turned off.

[0039] If Q1 is less than kQ0, and T is less than 2℃, then the ground temperature preheating heat source is turned on.

[0040] In all other cases except the two mentioned above, keep the air compressor waste heat fan running;

[0041] S3. When step S2 determines that the ground temperature preheating heat source needs to be activated, activate the ground temperature preheating heat source and perform a ground temperature preheating heat source determination; specifically as follows:

[0042] Open the ground temperature preheating damper and start the ground temperature preheating fan to deliver the preheated air to the entrance of the air intake shaft.

[0043] Calculate the heat supply Q2 for geothermal preheating and compare it with the heat requirement kQ0 for mine preheating airflow;

[0044] The heat supply Q2 for geothermal preheating can be calculated using the following formula:

[0045]

[0046] In the formula: Q2 is the heat of ground temperature preheating, in kW;

[0047] K τ The unsteady heat transfer coefficient between the surrounding rock and the airflow is expressed in kW / (m³). 2 ℃);

[0048] S represents the area of ​​shallow abandoned shafts and shallow goaf areas utilized for preheating the intake airflow with geothermal energy, in meters (m²). 2 ;

[0049] t r The average rock strata temperature is expressed in °C.

[0050] t1 is the temperature of the cold air at ground level, in °C;

[0051] t2 is the temperature of the air after preheating, in units of 2.0℃.

[0052] Compare Q1+Q2 with kQ0;

[0053] If Q1+Q2 is greater than kQ0, and T>5℃ at the same time, then turn off the ground temperature preheating fan and return to step S2.

[0054] If Q1+Q2 is less than kQ0, and T<2℃ at this time, then the heating unit is turned on to preheat the heat source.

[0055] In all other cases except the two mentioned above, keep the air compressor waste heat fan and the ground temperature preheating fan running.

[0056] S4. When step S3 determines that the heating unit needs to be turned on to preheat the heat source, the heating unit is started; specifically as follows:

[0057] Start the heater unit and initially operate at a low frequency;

[0058] Calculate the required additional heat Q3 to determine the operating power of the heating unit;

[0059] The energy supplement Q3 can be calculated using the following formula:

[0060] Q3 = kQ0 - Q1 - Q2

[0061] The power of the heater unit is adjusted in stages by a frequency converter so that the heat output of the heater unit is the same as that of Q3.

[0062] When the surface temperature rises and T > 5°C, shut down the preheating heat source of the heating unit and return to step S3.

[0063] S5. If the temperature is still lower than the set temperature after step S4 is executed, the alarm will be activated to issue an alarm and notify the operator to suspend the operation.

[0064] The beneficial effects of this invention are as follows:

[0065] 1. By constructing a multi-stage synergistic preheating system integrating air compressor waste heat, geothermal energy, and heater units, energy cascade utilization and cost optimization are achieved. The system prioritizes the use of air compressor waste heat for basic preheating, and the geothermal preheating unit is modified to form a stable heat exchange channel. The heater units only supplement heat in variable frequency mode under extreme operating conditions. Compared with traditional single heat source systems, the overall energy consumption of this system is greatly reduced, which not only overcomes the limitation of geothermal preheating capacity, but also significantly reduces the high-energy-consumption operation time of the heater.

[0066] 2. A dual-parameter control method that links heat calculation and temperature monitoring is adopted to effectively avoid frequent system start-ups and shutdowns. By calculating the heat supply of each heat source in real time and dynamically comparing it with the heat demand of the mine, combined with the air intake temperature threshold range, an advanced control mechanism is formed. This method predicts the heat source demand through heat balance and suppresses instantaneous fluctuation interference in the temperature buffer zone. Compared with a simple temperature feedback system, the frequency of equipment start-ups and shutdowns is greatly reduced, and the system has good stability. Attached Figure Description

[0067] Figure 1 This is a schematic diagram of a structure according to an embodiment of the present invention.

[0068] Figure 2 This is a schematic diagram of the structure of the PLC automatic control system of the present invention. Detailed Implementation

[0069] The relevant technical solutions will now be clearly and completely described with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0070] like Figure 1 As shown in the figure, the multi-heat source synergistic preheating mine intake airflow system disclosed in this embodiment includes an intake shaft 1, an air compressor waste heat recovery unit 2, a ground temperature preheating unit 3, a heater unit 4, and a temperature monitoring unit 5. Each unit is synergistically connected to the intake shaft inlet through pipelines to achieve multi-heat source staged preheating.

[0071] The intake shaft 1 serves as the main channel for the mine's intake airflow, connecting the surface and underground ventilation networks. A shaft entrance structure 11 is installed at its entrance, with adjustable air windows on the structure to regulate the amount of cold air entering the shaft directly.

[0072] The air compressor waste heat recovery unit 2 includes an air compressor 21, an air compressor waste heat fan 22, and an air compressor pipeline 23.

[0073] The air compressor 21 is located in the air compressor room at the entrance of the air intake shaft. The waste heat generated during operation is transported to the entrance of the air intake shaft through the air compressor pipeline 23. The air compressor waste heat fan 22 is installed in the pipeline to provide power for the flow of hot air in the air compressor pipeline.

[0074] Mining air compressors compress air into high-pressure gas for use in underground rock drilling and compressed air self-rescue, making them indispensable equipment in mining operations. Air compressors reliably dissipate heat during operation. The waste heat supply from air compressors is relatively stable, generating virtually no additional costs, thus offering excellent economic efficiency.

[0075] In this embodiment, there may be one or more air compressors installed in an air compressor room.

[0076] The air compressor pipe 23 is insulated to prevent heat loss.

[0077] The geothermal preheating unit 3 includes a shallow goaf area 31, waste rock 32, shallow abandoned shafts 33, a geothermal preheating fan 34, and a geothermal preheating damper 35.

[0078] Shallow goaf 31 is transformed into a preheating zone, which is filled with large pieces of waste rock 32. On the one hand, this allows for more thorough heat exchange between the cold air and the rock mass and waste rock within the goaf, improving the preheating airflow capacity; on the other hand, the waste rock filling provides support to the shallow goaf, enhancing its stability.

[0079] One end of the shallow goaf 31 is connected to the surface through a shallow abandoned shaft 33, facilitating the entry of cold air; the other end is connected to the intake shaft 1 through a shallow abandoned shaft. The shallow abandoned shaft consists of vertical shafts, inclined shafts, horizontal shafts, and ceilings.

[0080] At the connection between the shallow abandoned shaft 33 and the intake shaft 1, a preheating fan 34 and a ground temperature preheating damper 35 are installed. The fan provides airflow power, and the damper controls the opening and closing of the preheating channel. The damper is opened when ground temperature preheating airflow is needed in the cold season, and closed in the summer when ground temperature preheating airflow is not needed.

[0081] At a depth of approximately 30–50 meters underground is the isothermal zone, where the rock temperature is unaffected by seasonal air temperature changes; below the isothermal zone is the warming zone, where the rock temperature increases continuously with increasing depth.

[0082] When cold air passes through shallow abandoned mine shafts and shallow goaf areas located in the isothermal and warming zones, heat exchange occurs between the rock mass and the air, raising the airflow temperature. Therefore, ground temperature can be used as a heat source for preheating the intake airflow. Ground temperature as a heat source for preheating intake airflow is stable and relatively economical.

[0083] The heater unit 4 includes a heating unit 41 and a heating pipe 42.

[0084] The heating unit 41 is located in the ground heater unit room, and the heated air is delivered to the entrance of the air intake shaft through the heating pipe 42.

[0085] The heating unit can employ air heaters or hot air boilers, among other methods. It converts electrical or fossil fuel energy into heat energy to preheat the incoming airflow. It starts up when waste heat and ground temperature are insufficient to meet the demand, and its preheating capacity is controlled by adjusting the operating frequency via a frequency converter.

[0086] The temperature monitoring unit 5 is a temperature sensor, and there are two in total. One is installed 10 m below the connection between the shallow abandoned roadway 23 and the intake airway 1 to monitor the temperature of the air current in the intake airway. The other is installed on the ground to obtain the ground temperature data in real time.

[0087] Since the temperature of the cold air on the ground changes dynamically with time and seasons, in order to make this preheating system adapt to this dynamic change, ensure the stability of the temperature of the mine intake air current after preheating, and at the same time reduce the cost of preheating the intake air current and the management difficulty of the multi-heat-source combined preheating intake air current system, a supporting PLC automatic control system is set up.

[0088] As Figure 2 shown, the PLC automatic control system supporting this preheating system includes a ground industrial control computer, a PLC base station, a temperature sensor, an execution terminal and an alarm.

[0089] The ground industrial control computer serves as the control center for data reception, logical operation and instruction issuance.

[0090] The PLC base station is connected to the ground industrial control computer for communication, responsible for collecting sensor data and controlling the execution terminal.

[0091] The temperature sensor is connected to the PLC base station to upload temperature data in real time.

[0092] The execution terminal includes an air compressor waste heat fan, a ground temperature preheating air door, a ground temperature preheating fan, a heater unit and an air volume regulating air window for the wellhead building. Each component is independently connected in parallel to the PLC base station and receives start-stop and frequency adjustment instructions.

[0093] The alarm is connected to the PLC base station, and after receiving the base station instruction, it triggers an audible and visual alarm to respond to abnormal signals.

[0094] A method for regulating the temperature of the mine intake air current using the above preheating system is as follows:

[0095] S1. Perform temperature detection and set initial judgment as follows:

[0096] Through the temperature sensor installed 10 m below the entrance of the intake airway, the air current temperature T is monitored in real time.

[0097] The PLC system sets the target temperature threshold range as 2 - 5 °C. When T < 2 °C, the preheating system is triggered to start. When T > 5 °C, the heat source is triggered to turn off.

[0098] S2. When it is judged in step S1 that the temperature is lower than the set value, start the air compressor heat source and perform air compressor heat source judgment as follows:

[0099] When the airflow temperature T first drops below 2℃ and the air compressor is running, turn on the air compressor waste heat fan and transport the waste heat to the intake shaft entrance through the pipeline.

[0100] Calculate the heat supply Q1 from the waste heat of the air compressor and compare it with the heat requirement kQ0 for the preheated airflow in the mine;

[0101] The waste heat supplied by the air compressor, Q1, can be calculated using the following formula:

[0102]

[0103] In the formula: Q1 is the preheating heat of the air compressor waste heat, in kW;

[0104] η1 is the waste heat utilization coefficient of the air compressor, ranging from 0.6 to 0.8;

[0105] η2 is the load factor, representing the ratio of the average actual power consumption per hour to the maximum actual power consumption of the air compressor motor, ranging from 0.5 to 0.8.

[0106] η3 is the simultaneous use coefficient, which is the ratio of the installed power used simultaneously to the total installed power, and is generally 0.5 to 1.0.

[0107] N represents the rated installed power of the air compressor, in kW;

[0108] η is the efficiency of the air compressor motor, ranging from 0.85 to 0.95;

[0109] The heat required for preheating airflow in a mine, Q0, can be calculated using the following formula:

[0110] Q0 = 0.239Q b γC p (t2-t1)

[0111] In the formula: Q0 is the heat required for preheating airflow in the mine, in kW;

[0112] Q b This refers to the air intake volume of the intake shaft, expressed in cubic meters (m³). 3 / s;

[0113] γ is the weight percentage of cold air, in kg / m³. 3 ;

[0114] C p This is the specific heat of air at constant pressure, expressed in kcal / (kg℃).

[0115] t1 is the ground cold air temperature, in °C, obtained from a ground temperature sensor;

[0116] t2 is the temperature of the air after preheating, in units of 2.0℃.

[0117] Comparing Q1 with kQ0, k is the heat reserve coefficient for the preheated airflow, ranging from 1.1 to 1.3. Setting a reserve coefficient can reserve a safety margin for the system, covering extreme weather or heat source attenuation conditions, and improve system reliability.

[0118] If Q1 is greater than kQ0, and T is greater than 5℃, then the waste heat fan of the air compressor should be turned off.

[0119] If Q1 is less than kQ0, and T is less than 2℃, then the ground temperature preheating heat source is turned on.

[0120] In all other cases except the two mentioned above, keep the air compressor waste heat fan running;

[0121] S3. When step S2 determines that the ground temperature preheating heat source needs to be activated, activate the ground temperature preheating heat source and perform a ground temperature preheating heat source determination; specifically as follows:

[0122] Open the ground temperature preheating damper and start the ground temperature preheating fan to deliver the preheated air to the entrance of the air intake shaft.

[0123] Calculate the heat supply Q2 for geothermal preheating and compare it with the heat requirement kQ0 for mine preheating airflow;

[0124] The heat supply Q2 for geothermal preheating can be calculated using the following formula:

[0125]

[0126] In the formula: Q2 is the heat of ground temperature preheating, in kW;

[0127] K τ The unsteady heat transfer coefficient between the surrounding rock and the airflow is expressed in kW / (m³). 2 ℃);

[0128] S represents the area of ​​shallow abandoned shafts and shallow goaf areas utilized for preheating the intake airflow with geothermal energy, in meters (m²). 2 ;

[0129] t r The average rock strata temperature is expressed in °C.

[0130] t1 is the temperature of the cold air at ground level, in °C;

[0131] t2 is the temperature of the air after preheating, in units of 2.0℃.

[0132] Compare Q1+Q2 with kQ0;

[0133] If Q1+Q2 is greater than kQ0, and T>5℃ at the same time, then turn off the ground temperature preheating fan and return to step S2.

[0134] If Q1+Q2 is less than kQ0, and T<2℃ at this time, then the heating unit is turned on to preheat the heat source.

[0135] In all other cases except the two mentioned above, keep the air compressor waste heat fan and the ground temperature preheating fan running.

[0136] S4. When step S3 determines that the heating unit needs to be turned on to preheat the heat source, the heating unit is started; specifically as follows:

[0137] Start the heater unit and initially operate at a low frequency;

[0138] Calculate the required additional heat Q3 to determine the operating power of the heating unit;

[0139] The energy supplement Q3 can be calculated using the following formula:

[0140] Q3 = kQ0 - Q1 - Q2

[0141] The power of the heater unit is adjusted in stages by a frequency converter so that the heat output of the heater unit is the same as that of Q3.

[0142] When the surface temperature rises and T > 5°C, the preheating heat source of the heating unit is turned off and the process returns to step S3.

[0143] S5. If the temperature is still lower than the set temperature after step S4 is executed, the alarm will be activated to issue an alarm and notify the operator to suspend the operation.

[0144] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for regulating a multi-heat-source synergistic preheating mine intake airflow system, characterized in that, The multi-heat-source coordinated preheating mine intake airflow system used in the regulation method includes intake shaft, air compressor waste heat recovery unit, ground temperature preheating unit, heater unit and temperature monitoring unit; The intake shaft entrance is equipped with an adjustable ventilation window; the air compressor waste heat recovery unit includes an air compressor, a pipeline connecting the air compressor to the intake shaft entrance, and a waste heat fan installed inside the pipeline; the geothermal preheating unit includes a shallow goaf filled with waste rock, a shallow abandoned shaft connecting the shallow goaf to the intake shaft, a geothermal preheating fan and a geothermal preheating damper installed at the connection; the heater unit unit includes a heating unit arranged on the ground and a pipeline connecting the heating unit to the intake shaft entrance; the temperature monitoring unit includes a temperature sensor installed below the shaft connection and a temperature sensor installed on the ground; each unit is connected to the intake shaft entrance through pipelines to achieve multi-heat source staged preheating; The specific steps for adjustment are as follows: S1. Perform temperature detection and set initial judgment; The airflow temperature T is monitored in real time using a temperature sensor. The PLC automatic control system sets the target temperature threshold range to 2-5℃. When T < 2℃, the preheating system is triggered to start, and when T > 5℃, the heat source is triggered to shut down. S2. When step S1 determines that the temperature is lower than the set value, the air compressor heat source is activated, and the air compressor heat source is determined. When the airflow temperature T first drops below 2℃ and the air compressor is running, turn on the air compressor waste heat fan and transport the waste heat to the intake shaft entrance through the pipeline. Calculate the heat supply Q1 from the waste heat of the air compressor and compare it with the heat requirement kQ0 for the preheated airflow in the mine; The waste heat supplied by the air compressor, Q1, can be calculated using the following formula: In the formula: Q1 is the preheating heat of the air compressor waste heat, in kW; η1 is the waste heat utilization coefficient of the air compressor, ranging from 0.6 to 0.8; η2 is the load factor, representing the ratio of the average actual power consumption per hour to the maximum actual power consumption of the air compressor motor, ranging from 0.5 to 0.

8. η3 is the simultaneous use coefficient, which is the ratio of the installed power used simultaneously to the total installed power, and is generally 0.5 to 1.

0. N represents the rated installed power of the air compressor, in kW; η is the efficiency of the air compressor motor, ranging from 0.85 to 0.95; The heat required for preheating airflow in a mine, Q0, can be calculated using the following formula: In the formula: Q0 is the heat required for preheating airflow in the mine, in kW; Q b This refers to the air intake volume of the intake shaft / tunnel, expressed in cubic meters (m³). 3 / s; γ is the weight percentage of cold air, in kg / m³. 3 ; C p This is the specific heat of air at constant pressure, expressed in kcal / (kg℃). t1 is the temperature of the cold air at ground level, in °C; t2 is the temperature of the air after preheating, in units of 2.0℃. Compare Q1 with kQ0, where k is the heat reserve coefficient for the preheated airflow, ranging from 1.1 to 1.3; If Q1 is greater than kQ0, and T is greater than 5℃, then the waste heat fan of the air compressor should be turned off. If Q1 is less than kQ0, and T is less than 2℃, then the ground temperature preheating heat source is turned on. In all other cases except the two mentioned above, keep the air compressor waste heat fan running; S3. When step S2 determines that the ground temperature preheating heat source needs to be activated, activate the ground temperature preheating heat source and perform a ground temperature preheating heat source determination; specifically as follows: Open the ground temperature preheating damper and start the ground temperature preheating fan to deliver the preheated air to the entrance of the air intake shaft. Calculate the heat supply Q2 for geothermal preheating and compare it with the heat requirement kQ0 for mine preheating airflow; The heat supply Q2 for geothermal preheating can be calculated using the following formula: In the formula: Q2 is the heat of ground temperature preheating, in kW; K τ The unsteady heat transfer coefficient between the surrounding rock and the airflow is expressed in kW / (m³). 2 ℃); S represents the area of ​​shallow abandoned shafts and tunnels and shallow goaf areas that utilize geothermal preheating of the intake airflow, in meters. 2 ; t r The average rock strata temperature is expressed in °C. t1 is the temperature of the cold air at ground level, in °C; t2 is the temperature of the air after preheating, in units of 2.0℃. Compare Q1+Q2 with kQ0; If Q1+Q2 is greater than kQ0, and T>5℃ at the same time, then turn off the ground temperature preheating fan and return to step S2. If Q1+Q2 is less than kQ0, and T<2℃ at this time, then the heating unit is turned on to preheat the heat source. In all other cases except the two mentioned above, keep the air compressor waste heat fan and the ground temperature preheating fan running. S4. When step S3 determines that the heating unit needs to be turned on to preheat the heat source, the heating unit is started; specifically as follows: Start the heating unit and initially run it at a low frequency. Calculate the required additional heat Q3 to determine the operating power of the heating unit; The energy supplement Q3 can be calculated using the following formula: The power of the heating unit is adjusted in stages using a frequency converter to ensure that the heat output of the heating unit is the same as that of Q3. When the surface temperature rises and T > 5°C, shut down the preheating heat source of the heating unit and return to step S3. S5. If the temperature is still lower than the set temperature after step S4 is executed, the alarm will be activated to issue an alarm and notify the operator to suspend the operation.

2. The adjustment method as described in claim 1, characterized in that: The shallow abandoned shafts and tunnels are formed by a combination of vertical shafts, inclined shafts, and horizontal tunnels to create ventilation channels.

3. The adjustment method as described in claim 1, characterized in that: The heating unit in the heater unit adopts a frequency conversion control type heating device.

4. The adjustment method as described in claim 1, characterized in that: The shallow goaf of the geothermal preheating unit is connected to the surface through shallow abandoned shafts to form a cold air entry channel.

5. The adjustment method as described in claim 1, characterized in that: The air compressor waste heat recovery unit includes multiple air compressors connected in parallel.

6. The adjustment method as described in claim 1, characterized in that: The air compressor piping is insulated.

7. The adjustment method as described in claim 1, characterized in that: The heating unit is an air heater.

8. The adjustment method as described in claim 1, characterized in that: It is equipped with a PLC automatic control system, whose hardware includes a ground industrial computer, PLC base station, temperature sensor, execution terminal and alarm. The ground-based industrial control computer serves as the control center; the PLC base station communicates with the ground-based industrial control computer; the temperature sensor is connected to the PLC base station; the execution terminals include the air compressor waste heat fan, the ground temperature preheating damper, the ground temperature preheating fan, the heating unit, and the wellhead building regulating vent; each component of the execution terminal is independently connected in parallel with the PLC base station; the alarm is connected to the PLC base station.

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