A mine exhaust heat deep utilization device and method

Abstract

The present application relates to the technical field of mine exhaust heat utilization, and particularly relates to a mine exhaust heat deep utilization device and method. The present application collects mine exhaust heat by means of working medium in the exhaust heat collection module containing baffle, and transmits the working medium to the preheating module containing heating module to preheat the new air into the well, collects the working medium temperature, exhaust temperature and air pressure differential pressure of the inlet and outlet of the exhaust heat collection module and preheating module through the exhaust heat utilization control system, analyzes and obtains the effective utilization parameters of exhaust heat, adjusts the water pump power and fan power, and monitors the working medium temperature of the inlet of the preheating module to control the start and stop of the heating module. The present application dynamically adjusts the water pump power and fan power by analyzing the relative temperature change of the working medium and gas in the device, combining the temperature difference between the working medium, fully utilizes the mine exhaust heat, and monitors the working medium temperature to control the added heating module to prevent the freezing of the ventilation system.

Description

Technical Field

[0001] This invention relates to the field of waste heat utilization technology in mine ventilation, specifically to a device and method for deep utilization of waste heat from mine ventilation. Background Technology

[0002] Deep within mines, the temperature gradually rises due to the inherently high temperature of the rock strata and the heat generated by mining activities. Therefore, to ensure the continuation of mining operations, a ventilation system is needed to remove excess heat from the mine. Simultaneously, mine safety regulations require that the intake shaft of the ventilation system not freeze in low-temperature environments. Therefore, the waste heat from mine exhaust can be recovered and transferred to the ventilation system to prevent freezing due to low external temperatures.

[0003] However, existing mine ventilation systems directly input treated mine exhaust air into a water tank. Because the gas rises and exits rapidly after injection, heat transfer between the working fluid and the gas is insufficient, resulting in wasted heat. Furthermore, when the mine exhaust air temperature falls below the required level, the system cannot effectively maintain the temperature, easily leading to icing. Summary of the Invention

[0004] To address the technical problems of insufficient utilization of exhaust waste heat and the risk of icing in existing mine ventilation waste heat recovery devices, the present invention aims to provide a device and method for deep utilization of mine ventilation waste heat. The specific technical solution adopted is as follows:

[0005] A device for deep utilization of waste heat from mine exhaust ventilation, the device being used to collect waste heat from mine exhaust ventilation using a working fluid in a waste heat collection module containing baffles, and to transfer the working fluid to a preheating module containing a heating module to preheat the incoming fresh air; it also includes a waste heat utilization control system; the waste heat utilization control system includes:

[0006] Data acquisition module: used to acquire the working fluid temperature, exhaust air temperature and air pressure difference at the inlet and outlet of the waste heat collection module and the preheating module;

[0007] Waste heat utilization assessment module: used to obtain effective waste heat utilization parameters based on the relative change between the exhaust temperature and the working fluid temperature of the waste heat collection module, combined with the relative change between the exhaust temperature and the working fluid temperature of the preheating module, and the transmission loss of the working fluid.

[0008] Waste heat utilization adjustment module: used to adjust the water pump power based on the overall working fluid temperature difference between the waste heat collection module and the preheating module, combined with the waste heat effective utilization parameters and the transmission loss of the working fluid; when adjusting the water pump power, the fan power is adjusted based on the waste heat effective utilization parameters, combined with the change of the exhaust temperature and the air pressure difference.

[0009] Heating module control module: used to monitor the working fluid temperature at the inlet of the preheating module and control the start and stop of the heating module.

[0010] Furthermore, the method for obtaining the waste heat effective utilization parameters includes:

[0011] The exhaust waste heat loss rate is obtained based on the relative change between the exhaust air temperature and the working fluid temperature of the waste heat collection module.

[0012] The waste heat utilization rate of the exhaust is obtained based on the relative change between the exhaust temperature and the working fluid temperature of the preheating module.

[0013] By integrating the exhaust waste heat loss rate, the exhaust waste heat utilization rate, and the transmission loss of the working fluid, effective waste heat utilization parameters are obtained; the exhaust waste heat utilization rate is positively correlated with the effective waste heat utilization parameters; both the exhaust waste heat loss rate and the transmission loss of the working fluid are negatively correlated with the effective waste heat utilization parameters.

[0014] Furthermore, the method for obtaining the exhaust waste heat loss rate includes:

[0015] The cooling rate of the mine exhaust is obtained based on the temperature difference between the exhaust inlet and outlet of the waste heat collection module; the heating rate of the working fluid is obtained based on the temperature difference between the working fluid inlet and outlet of the waste heat collection module; and the exhaust waste heat loss is obtained based on the difference between the cooling rate of the mine exhaust and the heating rate of the working fluid.

[0016] The exhaust waste heat loss rate is obtained based on the ratio between the exhaust temperature at the exhaust inlet of the waste heat collection module and the exhaust waste heat loss amplitude; the exhaust waste heat loss amplitude is positively correlated with the exhaust waste heat loss rate; the exhaust temperature at the exhaust inlet of the waste heat collection module is negatively correlated with the exhaust waste heat loss rate.

[0017] Furthermore, the method for obtaining the waste heat utilization rate of the exhaust air includes:

[0018] The preheating range of the incoming fresh air is obtained based on the difference in exhaust air temperature between the fresh air inlet and the fresh air outlet of the preheating module; the cooling range of the working fluid is obtained based on the difference in working fluid temperature between the working fluid inlet and the working fluid outlet of the preheating module; and the waste heat loss range of the working fluid is obtained based on the difference between the preheating range of the incoming fresh air and the cooling range of the working fluid.

[0019] The exhaust waste heat utilization rate is obtained based on the ratio of the working fluid temperature at the working fluid inlet of the preheating module to the magnitude of the working fluid waste heat loss; the magnitude of the working fluid waste heat loss is negatively correlated with the exhaust waste heat utilization rate; the working fluid temperature at the working fluid inlet of the preheating module is positively correlated with the exhaust waste heat utilization rate.

[0020] Furthermore, the method for obtaining the transmission loss includes:

[0021] The transmission loss is obtained based on the difference between the working fluid temperature at the working fluid outlet of the waste heat collection module and the working fluid temperature at the working fluid inlet of the preheating module.

[0022] Furthermore, the method for adjusting the water pump power includes:

[0023] The average working fluid temperature at the working fluid inlet and outlet of the waste heat collection module is taken as the overall working fluid temperature; the average working fluid temperature at the working fluid inlet and outlet of the preheating module is taken as the overall working fluid temperature.

[0024] Based on the difference between the overall working fluid temperature of the waste heat collection module and the overall working fluid temperature of the preheating module, and in conjunction with the transmission loss, the module temperature difference parameter is obtained; the module temperature difference parameter and the waste heat effective utilization parameter are fused to obtain the adaptation coefficient of the device operating parameters; both the module temperature difference parameter and the waste heat effective utilization parameter are positively correlated with the adaptation coefficient;

[0025] When the adaptation coefficient is less than the preset adaptation threshold, it is determined to adjust the water pump power: based on the current water pump power and the module temperature difference parameter, the adjusted target water pump power is obtained; the water pump power and the module temperature difference parameter are both positively correlated with the target water pump power.

[0026] Furthermore, the method for adjusting the fan power includes:

[0027] The adjustment of the fan power includes adjusting the exhaust fan power of the exhaust fan in the well and the preheating fan power of the preheating module.

[0028] A first power adjustment coefficient is obtained by integrating the pressure difference between the exhaust inlet and outlet of the waste heat collection module and the temperature difference of the exhaust air. The pressure difference of the waste heat collection module is negatively correlated with the first power adjustment coefficient, while the temperature difference of the exhaust air from the waste heat collection module is positively correlated with the first power adjustment coefficient. Based on the current exhaust fan power and the first power adjustment coefficient, the adjusted target power of the exhaust fan is obtained. Both the exhaust fan power and the first power adjustment coefficient are positively correlated with the target power of the exhaust fan.

[0029] A second power adjustment coefficient is obtained by combining the pressure difference between the preheating module's exhaust inlet and outlet and the temperature difference of the exhaust air. The pressure difference of the preheating module is negatively correlated with the second power adjustment coefficient, while the temperature difference of the preheating module's exhaust air is positively correlated with the first power adjustment coefficient. Based on the current preheating fan power and the second power adjustment coefficient, the adjusted target power of the preheating fan is obtained. Both the preheating fan power and the second power adjustment coefficient are positively correlated with the target power of the preheating fan.

[0030] Furthermore, the method for controlling the start and stop of the heating module by monitoring the working fluid temperature at the inlet of the preheating module includes:

[0031] When the working fluid temperature at the working fluid inlet of the preheating module is lower than the preset minimum temperature threshold for a duration exceeding a preset time range, the heating module is started, and the heating module is turned off when the working fluid temperature at the working fluid inlet of the preheating module is higher than the preset minimum temperature threshold for a duration exceeding the preset time range.

[0032] Furthermore, both the adjustment of the water pump power and the adjustment of the fan power employ PID control algorithms.

[0033] This invention proposes a method for deep utilization of waste heat from mine exhaust ventilation. The method utilizes any one of the waste heat utilization devices for mine exhaust ventilation to utilize the waste heat from the mine exhaust ventilation.

[0034] The present invention has the following beneficial effects:

[0035] This invention extends the contact time between the working fluid and the gas within the waste heat collection module using baffles, thus more fully collecting waste heat from mine exhaust. Furthermore, the data acquisition module collects data to provide an analytical basis for the waste heat utilization control system. The waste heat utilization evaluation module analyzes the relative changes in exhaust temperature and working fluid temperature, as well as the transmission loss of the working fluid, to obtain effective waste heat utilization parameters. This characterizes the effective utilization features of the waste heat deep utilization device for mine exhaust waste heat, providing a basis for subsequent adjustments to the device's operating status. Finally, the waste heat utilization adjustment module analyzes the overall working fluid temperature differences between different modules, combined with the effective utilization of waste heat... By dynamically adjusting the pump power based on parameters and working fluid transmission losses, the working fluid flow rate is adjusted, improving the adaptability of the device, reducing heat loss, and increasing waste heat utilization efficiency. Furthermore, when adjusting the pump power, the fan power is dynamically adjusted based on waste heat utilization parameters, combined with changes in exhaust temperature and air pressure difference, to match the air velocity with the heat exchange situation, maintain the stability of the heat exchange system, ensure efficient heat exchange, improve waste heat utilization efficiency, prevent fan overload, and extend equipment life. A heating module is further added, and the inlet working fluid temperature of the preheating module is monitored through the waste heat utilization control system to control the start and stop of the heating module, preventing the ventilation system from icing. This invention analyzes the relative temperature changes of the working fluid and gas within the device, combines the temperature differences between the working fluids, dynamically adjusts the pump power and fan power, fully utilizes the waste heat from mine exhaust, monitors the working fluid temperature, and controls the added heating module to prevent the ventilation system from icing. Attached Figure Description

[0036] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 A schematic diagram of a waste heat utilization device for mine ventilation provided in an embodiment of the present invention;

[0038] Figure 2 This is a system block diagram of a waste heat utilization control system provided in one embodiment of the present invention;

[0039] Figure 3 This is a flowchart illustrating a method for obtaining parameters for effective waste heat utilization, as provided in an embodiment of the present invention.

[0040] The following are labeled in the diagram: 1. Exhaust fan; 2. First L-shaped pipe; 3. Drying box; 4. Sodium hydroxide drying plate; 5. Curved pipe; 6. Spiral pipe; 7. Liquid outlet valve; 8. Liquid inlet valve; 9. Second L-shaped pipe; 10. Box body; 11. First water inlet pipe; 12. First water outlet pipe; 13. Valve; 14. Air outlet pipe; 15. Water storage tank; 16. Second water outlet pipe; 17. Air outlet; 18. Air inlet; 19. Heating module; 20. Baffle plate. Detailed Implementation

[0041] To further illustrate the technical means and effects adopted by the present invention to achieve its intended purpose, the following, in conjunction with the accompanying drawings and preferred embodiments, details the specific implementation, structure, features, and effects of a mine ventilation waste heat deep utilization device and method proposed according to the present invention. In the following description, different "one embodiment" or "another embodiment" do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics in one or more embodiments can be combined in any suitable form.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0043] This invention provides a device for deep utilization of waste heat from mine exhaust ventilation. The device includes a main body, such as a waste heat collection module with baffles and a preheating module with a heating module. In addition to the main body, a waste heat utilization control system is included. This control system controls the heating module, adjusts the power of the water pump and the fan, and maximizes the utilization of waste heat from mine exhaust ventilation, reducing the risk of icing in the ventilation system.

[0044] The following description, in conjunction with the accompanying drawings, details the specific scheme of the waste heat utilization device and method for mine ventilation provided by the present invention.

[0045] Please see Figure 1The diagram illustrates a schematic of a waste heat utilization device for mine exhaust ventilation according to an embodiment of the present invention. An exhaust fan 1 draws in air from inside the mine and into the waste heat utilization device. It is connected to a drying chamber 3 via a first L-shaped pipe 2. The drying chamber 3 contains a sodium hydroxide drying plate 4 for drying the mine exhaust ventilation. A curved pipe 5 connects the drying chamber 3 to a spiral pipe 6, which contains liquid bromine for treating methane gas. An outlet valve 7 and an inlet valve 8 control the flow of liquid in and out of the spiral pipe 6. The pre-treated mine exhaust ventilation enters the chamber through a second L-shaped pipe 9. 10. Finally, the gas leaves through the outlet pipe 14. The gas comes into contact with the working fluid inside the housing 10, and the contact time between the working fluid and the gas is extended by the baffle plate 20, so as to collect the waste heat of the mine exhaust more fully. The working fluid enters the housing 10 through the first water inlet pipe 11, flows through the valve 13 and then through the first water outlet pipe 12, enters the water storage tank 15, and flows out through the second water outlet pipe 16. The fresh air entering the mine enters the water storage tank 15 through the air inlet 18 and leaves through the air outlet 17. The working fluid preheats the fresh air entering the mine in the water storage tank 15. The heating module 19 is located at the bottom of the water storage tank 15 for emergency heating to reduce the risk of icing in the ventilation system.

[0046] The waste heat collection module includes a second L-shaped pipe 9, a box 10, a first water inlet pipe 11, an air outlet pipe 14, and a baffle plate 20; the preheating module includes a water storage tank 15, a second water outlet pipe 16, an air outlet 17, an air inlet 18, a heating module 19, and a baffle plate 20. The two modules are connected by the first water outlet pipe 12 and a valve 13.

[0047] It should be noted that, Figure 1 The diagram only illustrates the connection relationships of each component and explains the most essential purpose of each component. For example, the installation of a one-way valve at the second L-shaped pipe 9 to prevent liquid from entering the spiral pipe 6 and the installation of a gas-water separator to allow gas and working fluid to flow out from the corresponding outlet are common technical means and will not be described in detail here.

[0048] It should be noted that an air purification device, such as an activated carbon filter, is connected after the exhaust pipe 14 to ensure that the gas emissions meet the requirements and avoid causing air pollution.

[0049] Sensors are installed in the waste heat recovery device of the mine exhaust to collect the required data. The specific sensors and their installation locations are shown below:

[0050] Temperature sensors are installed at: the outlet of the second L-shaped pipe 9 at the bottom of the housing 10, to monitor the exhaust temperature T9 at the exhaust inlet of the waste heat collection module; and at the outlet of the air outlet pipe 14 at the top of the housing 10, to monitor the exhaust temperature T at the exhaust outlet of the waste heat collection module. 14 The bottom of housing 10 is used to monitor the medium temperature T at the outlet of the waste heat collection module. 10downThe top of housing 10 is used to monitor the medium temperature T at the inlet of the waste heat collection module. 10_up The bottom of water storage tank 15 is used to monitor the medium temperature T at the inlet of the preheating module. 15down The top of water storage tank 15 is used to monitor the medium temperature T at the outlet of the preheating module. 15down Air inlet 18 is used to monitor the exhaust air temperature T at the fresh air inlet of the preheating module. 18 ;17 Air outlet, used to monitor the exhaust air temperature T at the fresh air outlet of the preheating module. 17 Both the top and bottom are inside the container;

[0051] Pressure sensors are installed at the second L-shaped pipe 9, the outlet pipe 14, the outlet of 17, and the inlet 18, respectively, to monitor wind pressure data.

[0052] Data collected by various sensors is transmitted to the waste heat utilization control system. The data is then processed and analyzed by a locally deployed computing unit or transmitted to the cloud. The corresponding data is then fed back to the waste heat utilization control system, which in turn sends corresponding control signals to each device.

[0053] Please see Figure 2 The diagram shows a system block diagram of a waste heat utilization control system provided by the present invention, including a data acquisition module 101, a waste heat utilization evaluation module 102, a waste heat utilization adjustment module 103, and a heating module control module 104.

[0054] Data acquisition module 101: used to acquire the working fluid temperature, exhaust air temperature and air pressure difference at the inlet and outlet of the waste heat collection module and the preheating module.

[0055] First, we need to acquire various data to provide a foundation for subsequent analysis.

[0056] The working fluid temperature and exhaust air temperature data are directly obtained through temperature sensors, as described in the sensor setup section; the air pressure difference of the waste heat collection module is the difference Y between the air pressure data of the second L-shaped pipe 9 and the air pressure data of the outlet pipe 14. 9，14 The air pressure difference of the preheating module is the difference Y between the air pressure data at the outlet 17 and the air pressure data at the inlet 18. 17，18 The air pressure data of the second L-shaped pipe 9 and the air pressure data of the air inlet 18 are the minuends.

[0057] In one embodiment of the present invention, the data acquisition frequency is 10Hz, and the medium is water. In other embodiments of the present invention, the acquisition frequency can be adjusted, and media such as ethylene glycol solution can be used to collect waste heat from mine exhaust and preheat fresh air entering the mine.

[0058] It should be noted that the analysis method is consistent for each collection moment, and the collected data is analyzed in real time. Here, we only take the latest collection moment as an example. The data used in subsequent analyses are all data at the current moment, and the feature parameters obtained are all feature parameters at the current moment.

[0059] Waste heat utilization assessment module 102: used to obtain effective waste heat utilization parameters based on the relative changes in exhaust temperature and working fluid temperature of the waste heat collection module, combined with the relative changes in exhaust temperature and working fluid temperature of the preheating module, and the transmission loss of the working fluid.

[0060] Considering that the change in exhaust temperature of the waste heat collection module reflects the heat release of the mine exhaust air, and the change in working fluid temperature reflects the heat absorption of the working fluid, the relative change between the exhaust temperature and the working fluid temperature of the waste heat collection module reflects the characteristics of the working fluid absorbing heat from the mine exhaust air. Similarly, the change in exhaust temperature of the preheating module reflects the heat release of the working fluid, and the change in exhaust temperature reflects the heat absorption of the incoming fresh air. The relative change between the exhaust temperature and the working fluid temperature of the preheating module reflects the characteristics of the working fluid transferring heat to the incoming fresh air and the preheating of the incoming fresh air. Combining these two factors reflects the effective transfer of heat from the mine exhaust air to the incoming fresh air. Furthermore, considering the loss of the working fluid during the transfer between the waste heat collection module and the preheating module, the transfer loss of the working fluid is also considered to obtain parameters for effective waste heat utilization. This characterizes the effective utilization characteristics of the waste heat deep utilization device for mine exhaust waste heat, providing a basis for subsequent adjustments to the device's operating status.

[0061] Preferably, in one embodiment of the present invention, please refer to Figure 3 The flowchart illustrates a method for obtaining parameters for effective waste heat utilization according to an embodiment of the present invention, specifically including:

[0062] Step S201: Obtain the exhaust waste heat loss rate based on the relative change between the exhaust temperature and the working fluid temperature of the waste heat collection module.

[0063] As an example: Based on the temperature difference between the exhaust air inlet and outlet of the waste heat collection module, the cooling rate of the mine exhaust air is obtained. Specifically, since the mine exhaust air is at a higher temperature when it enters the waste heat collection module, its temperature decreases after transferring heat to the working fluid, therefore ΔT 9，14 =T9-T 14 ΔT 9，14 This indicates the temperature drop of the mine exhaust ventilation, representing the heat release of waste heat from the mine exhaust ventilation; the difference is expressed as T9-T. 14 This shows the difference in exhaust temperature between the exhaust inlet and outlet of the waste heat collection module;

[0064] The temperature rise of the working fluid is obtained based on the temperature difference between the working fluid inlet and outlet of the waste heat collection module. Specifically, since the working fluid is at a lower temperature when it enters the waste heat collection module, its temperature rises after absorbing heat from the mine exhaust air, therefore ΔT 10 =T 10_down -T 10_up ΔT 10 This indicates the temperature rise, representing the heat absorption of the working fluid and the extent of waste heat collection; the difference is expressed in T. 10_down -T 10_up This shows the difference in working fluid temperature between the inlet and outlet of the waste heat collection module.

[0065] The magnitude of waste heat loss in the mine exhaust is determined by the difference between the cooling rate of the exhaust air and the heating rate of the working fluid. Specifically, according to the second law of thermodynamics, the heat released by the mine exhaust air is not completely absorbed by the working fluid, therefore ΔT s =ΔT 9，14 -ΔT 10 ΔT s The magnitude of exhaust heat loss is expressed as a difference, expressed in ΔT. 9，14 -ΔT 10 It shows the difference between the cooling range of mine exhaust and the heating range of the working fluid, and quantitatively describes the characteristics of exhaust heat loss;

[0066] The exhaust heat loss rate is obtained by comparing the exhaust temperature at the exhaust inlet of the waste heat collection module with the magnitude of exhaust heat loss. Considering that a larger exhaust heat loss indicates a greater temperature drop in the mine exhaust relative to a greater temperature rise in the working fluid, more heat may not be absorbed, resulting in a higher waste heat loss rate. Simultaneously, a higher exhaust temperature at the exhaust inlet generally leads to higher heat transfer efficiency and a lower waste heat loss rate. Therefore, the magnitude of exhaust heat loss and the exhaust heat loss rate are positively correlated; conversely, the exhaust temperature at the exhaust inlet of the waste heat collection module is negatively correlated with the exhaust heat loss rate.

[0067] Specifically, α s This indicates the waste heat loss rate of the exhaust air. It is expressed as a ratio. It represents the ratio between exhaust air temperature and exhaust waste heat loss, which can be regarded as the amount of waste heat loss per unit temperature. At the same time, the range is controlled by the linear normalization function norm().

[0068] It should be noted that the temperature inside the mine is high, and the exhaust temperature T9 is not zero; the exhaust waste heat loss rate is only used to provide a basis for subsequent calculations and to characterize the waste heat loss situation, and is not directly used as an indicator of the working status of the device.

[0069] Step S202: Obtain the exhaust waste heat utilization rate based on the relative change between the exhaust temperature and the working fluid temperature of the preheating module.

[0070] As an example: the preheating range of the incoming fresh air is obtained based on the temperature difference between the fresh air inlet and outlet of the preheating module; specifically, since the incoming fresh air is at a low temperature when entering the preheating module, its temperature rises after absorbing heat from the working fluid, therefore ΔT 17，18 =T 17 -T 18 ΔT 17，18 This indicates the preheating range, representing the heat absorption of the incoming fresh air; the difference is expressed in T. 17 -T 18 This indicates the difference in exhaust air temperature between the fresh air inlet and the fresh air outlet of the preheating module;

[0071] The temperature drop of the working fluid is obtained based on the temperature difference between the working fluid inlet and outlet of the preheating module. Specifically, since the working fluid enters the preheating module at a higher temperature, its temperature decreases after transferring heat to the incoming fresh air, therefore ΔT 15 =T 15_down -T 15_up ΔT 15 This indicates the degree of cooling of the working fluid, representing the amount of heat released by the working fluid;

[0072] The extent of waste heat loss of the working fluid is obtained by considering the difference between the preheating rate of the incoming fresh air and the cooling rate of the working fluid. Specifically, since the heat released by the working fluid is not completely absorbed by the incoming fresh air, ΔT u =ΔT 15 -ΔT 17，18 ΔT u The magnitude of waste heat loss of the working fluid is expressed as a difference, expressed in ΔT. 15 -ΔT 17,18 It indicates the difference between the preheating range of the incoming and outgoing fresh air and the cooling range of the working fluid, and quantitatively describes the heat loss characteristics of the working fluid;

[0073] The exhaust waste heat utilization rate is obtained by comparing the working fluid temperature at the preheating module inlet with the ratio of working fluid waste heat loss. Considering that a higher working fluid temperature entering the preheating module facilitates heat transfer to the incoming fresh air, resulting in higher transfer efficiency, and a smaller working fluid waste heat loss, indicating a smaller decrease in working fluid temperature compared to a larger increase in incoming fresh air temperature, the preheating effect of mine exhaust on the incoming fresh air is better, leading to a higher waste heat utilization rate. Therefore, the working fluid waste heat loss is negatively correlated with the exhaust waste heat utilization rate, while the working fluid temperature at the preheating module inlet is positively correlated with the exhaust waste heat utilization rate.

[0074] Specifically, β u This indicates the utilization rate of waste heat from exhaust ventilation. It is expressed as a ratio. This represents the ratio between the working fluid temperature at the working fluid inlet and the magnitude of the working fluid waste heat loss. It can be regarded as the multiple of waste heat loss per unit temperature, and the range is controlled by the linear normalization function norm().

[0075] Step S203: Combine the exhaust waste heat loss rate, exhaust waste heat utilization rate and working fluid transmission loss to obtain effective waste heat utilization parameters.

[0076] As an example, the transmission loss is obtained based on the difference between the working fluid temperature at the outlet of the waste heat collection module and the working fluid temperature at the inlet of the preheating module.

[0077] Specifically, because the working fluid leaves the waste heat collection module at a high temperature and experiences heat loss during the transmission path, it arrives at the preheating module at a lower temperature, therefore ΔT 10，15 =T 10_down -T 15_down ΔT 10，15 It represents the transmission loss, and expresses the difference between the working fluid temperature at the outlet of the waste heat collection module and the working fluid temperature at the inlet of the preheating module by means of the difference, and quantitatively describes the loss characteristics of working fluid transmission.

[0078] The calculation formulas for parameters of effective waste heat utilization include:

[0079]

[0080] Where, δ u Represents the parameters for effective waste heat utilization; norm() represents the linear normalization function; α s Indicates the waste heat loss rate of exhaust air; β u Indicates the waste heat utilization rate of exhaust ventilation; ΔT 10，15 This indicates transmission loss.

[0081] In the calculation formula for the effective utilization parameter of waste heat, the lower the exhaust waste heat loss rate, the better the heat transfer from the mine exhaust to the working fluid, the more effectively the exhaust heat is utilized, and the larger the effective utilization parameter of waste heat; the higher the exhaust waste heat utilization rate, the better the preheating effect of the working fluid on the incoming fresh air, and the larger the effective utilization parameter of waste heat; the lower the transmission loss of the working fluid, the less heat loss during the transmission between the two modules, the better the working state of the waste heat deep utilization device, and the larger the effective utilization parameter of waste heat; the exhaust waste heat utilization rate is positively correlated with the effective utilization parameter of waste heat; the exhaust waste heat loss rate and the transmission loss of the working fluid are both negatively correlated with the effective utilization parameter of waste heat.

[0082] Waste heat utilization adjustment module 103: used to adjust the water pump power based on the overall working fluid temperature difference between the waste heat collection module and the preheating module, combined with the waste heat effective utilization parameters and the transmission loss of the working fluid; when adjusting the water pump power, the fan power is adjusted based on the waste heat effective utilization parameters combined with the change of exhaust temperature and the air pressure difference.

[0083] The waste heat utilization evaluation module 102 obtains the effective utilization parameters of waste heat, indicating the effective utilization characteristics of the waste heat utilization device for mine exhaust waste heat. It also considers that the waste heat collection module transfers heat to the working fluid, while the preheating module uses the working fluid to transfer heat to the incoming fresh air. The overall working fluid temperature difference between the waste heat collection module and the preheating module reflects the difference in heat exchange capacity between the two modules, indirectly demonstrating the heat exchange capacity of the waste heat collection module. At the same time, it avoids the impact of heat loss during working fluid transmission, accurately assesses the difference in heat exchange capacity, and adjusts the water pump power based on the overall working fluid temperature difference between the waste heat collection module and the preheating module, combined with the effective utilization parameters of waste heat and the transmission loss of the working fluid. By dynamically adjusting the water pump power, the working fluid flow rate is adjusted, improving the adaptability of the device, reducing heat loss, and improving the waste heat utilization efficiency.

[0084] Preferably, in one embodiment of the present invention, considering the presence of the baffle 20 and the relatively uniform temperature distribution inside the container, the average working fluid temperature at the working fluid inlet and outlet of the waste heat collection module is taken as the overall working fluid temperature; the average working fluid temperature at the working fluid inlet and outlet of the preheating module is taken as the overall working fluid temperature.

[0085] Based on the difference between the overall working fluid temperature of the waste heat collection module and the overall working fluid temperature of the preheating module, and combined with the transmission loss, the module temperature difference parameter is obtained.

[0086] As an example: Considering that the working fluid temperature of the waste heat collection module is higher and the working fluid temperature of the preheating module is lower, heat is transferred from the waste heat collection module to the preheating module, and there are losses during the working fluid transfer process. Therefore, the formula for calculating the module temperature difference parameter is: in Indicates the module temperature difference parameter. This indicates the overall working fluid temperature inside chamber 10; ΔT represents the overall working fluid temperature inside the 10 water storage tanks. 10，15 This represents transmission loss. It is expressed as an interpolation method. This shows the overall working fluid temperature difference between the waste heat collection module and the preheating module. The larger the value, the stronger the heat exchange capacity of the waste heat collection module compared to the preheating module, which indirectly reflects the stronger ability of the waste heat collection module to collect heat from the mine exhaust.

[0087] Further integration of module temperature difference parameters and waste heat effective utilization parameters to obtain the adaptation coefficient of the device's operating parameters; considering that the larger the module temperature difference parameter, the stronger the waste heat collection module's ability to collect heat from the mine exhaust, and the larger the waste heat effective utilization parameter, the more effectively the device can utilize the waste heat from the mine exhaust, both the module temperature difference parameter and the waste heat effective utilization parameter are positively correlated with the adaptation coefficient.

[0088] As an example, the formula for calculating the fitness coefficient includes: Where ρ represents the fitness coefficient; norm() represents the linear normalization function; Indicates the module temperature difference parameter; δ u This indicates the parameters for effective utilization of waste heat.

[0089] In the formula for calculating the fitness coefficient, the module temperature difference parameter is processed through a linear normalization function, so that... With δ u To be of the same order of magnitude and eliminate the influence of dimensions, avoid The value is too large and dominates the calculation result; at the same time, ensure The positive correlation with ρ indicates that the larger the fitness coefficient, the better the working condition of the device and the less adjustment is required.

[0090] When the adaptation coefficient is less than the preset adaptation threshold, the water pump power is adjusted: the target water pump power after adjustment is obtained based on the current water pump power and the module temperature difference parameter.

[0091] As an example, considering that the larger the module temperature difference parameter, the stronger the waste heat collection module's ability to collect heat from the mine exhaust, it indicates that there is sufficient heat in the mine exhaust, which can increase the pump power, improve the working fluid's absorption rate of waste heat, reduce the working fluid's residence time in the transmission path, reduce transmission loss, increase the working fluid temperature entering the preheating module, increase the temperature difference between the working fluid temperature of the preheating module and the temperature of the incoming fresh air, which is more conducive to heat exchange and ultimately makes full use of the waste heat from the mine exhaust.

[0092] Conversely, the smaller the module temperature difference parameter, the weaker the waste heat collection module's ability to collect heat from the mine exhaust. This requires reducing the pump power, extending the heat exchange time between the working fluid and the mine exhaust, reducing pipe wear caused by friction between the working fluid and the pipes, improving equipment durability, and reducing maintenance needs. Therefore, both the pump power and the module temperature difference parameter are positively correlated with the target pump power.

[0093] Specifically, the preset adaptation threshold is 0.6, the water pump is installed at valve 13, and the calculation formula for the target water pump power includes: Where P 13 P represents the target pump power. t This indicates the current pump power; f() is used to... Positive correlation is mapped to -1 to 1; This indicates the module temperature difference parameter.

[0094] In the formula for calculating the target pump power, the f() function is used to... Mapped to -1 to 1, thus making Being between 0 and 2, it can affect P. t Adjust the zoom in and out. The larger the value, the more positively correlated the result after the f() function mapping. The larger it is, the more it affects P. t To perform amplification adjustment; the f() function can be used to... x represents the independent variable, x min x represents the minimum value of the independent variable. max The maximum value of the independent variable, For conventional linear normalization, It is used as the independent variable to obtain the mapped value.

[0095] It should be noted that the extreme values ​​of the independent variables used in linear normalization can be obtained by building a three-dimensional geometric model in Fluent, including a waste heat collection module, a preheating module, and a flow medium channel; setting boundary conditions, such as mine exhaust temperature, flow rate, working fluid temperature, and working fluid flow rate, and using the energy equation to calculate the heat transfer; after running the simulation, extracting heat transfer data at different times, and statistically analyzing the maximum and minimum values ​​of each key parameter; alternatively, before the device automatically adjusts, a step size of 10% can be set, from 10% to 100%, to combine the power of each fan and pump, collect experimental data, and provide a basis for linear normalization; the f() function can also be a hyperbolic tangent function, both of which are well-known techniques in the art and will not be elaborated here.

[0096] Considering that the operating parameters of the water pump in the waste heat deep utilization device change when the water pump power is adjusted, the corresponding fan also needs to be adjusted to change the exhaust flow rate; considering that the change in exhaust temperature reflects the heat exchange characteristics of mine exhaust and fresh air entering the mine, and the air pressure difference reflects the load intensity of the fan, the fan power is adjusted according to the waste heat effective utilization parameters combined with the changes in exhaust temperature and air pressure difference to match the air velocity with the heat exchange situation, maintain the stability of the heat exchange system, ensure efficient heat exchange, improve waste heat utilization efficiency, prevent fan overload, and extend equipment life.

[0097] Preferably, in one embodiment of the present invention, there is an exhaust fan 1 controlling the mine exhaust ventilation of the waste heat collection module and an air inlet 18 controlling the fresh air entering the mine of the preheating module. Therefore, adjusting the fan power includes adjusting the exhaust fan power of the exhaust fan 1 in the mine and the preheating fan power of the preheating module.

[0098] The first power adjustment coefficient is obtained by combining the pressure difference between the exhaust inlet and outlet of the waste heat collection module and the temperature difference of the exhaust air. Considering that a larger pressure difference indicates greater internal wind resistance of the module and a greater load on the fan, long-term operation under high pressure difference may lead to fatigue, wear, or even damage of mechanical components, resulting in overload, the fan power should be smaller. Conversely, a larger temperature difference indicates that the waste heat collection module can effectively collect exhaust waste heat, which can increase the fan power, increase the exhaust flow rate, increase the turbulence of the airflow, and improve the overall waste heat utilization rate. Therefore, the pressure difference of the waste heat collection module is negatively correlated with the first power adjustment coefficient, while the temperature difference of the exhaust air of the waste heat collection module is positively correlated with the first power adjustment coefficient.

[0099] Based on the current exhaust fan power and the first power adjustment coefficient, the adjusted target exhaust fan power is obtained. Considering that the target fan power is adjusted based on the current fan power, the larger the current fan power, the larger the adjusted target fan power. At the same time, the larger the first power adjustment coefficient, the more the fan power needs to be increased. Therefore, both the exhaust fan power and the first power adjustment coefficient are positively correlated with the exhaust fan target power.

[0100] As an example: the formula for calculating the target power of an exhaust fan includes:

[0101]

[0102] Among them, P w_1 P represents the target power of the exhaust fan after the current adjustment. w_1，t This indicates the current exhaust fan power; Represents the first power regulation coefficient; norm() represents the linear normalization function; ΔT 9，14 Indicates the temperature drop of mine exhaust ventilation; Y 9，14 This represents the wind pressure difference of the waste heat collection module; f() is used to... Positive correlation is mapped to -1 to 1.

[0103] In the formula for calculating the target power of the exhaust fan, the pressure difference is negatively correlated by taking the reciprocal form. Linear normalization is then used to limit the range, eliminating dimensions and ensuring that temperature and pressure parameters are on the same order of magnitude, avoiding the result being dominated by a single parameter due to differences in order of magnitude. The f() function is then used to... The positive correlation is mapped to -1 to 1, which allows the first power regulation coefficient to increase or decrease the wind turbine power.

[0104] Similarly, the pressure difference between the preheating module's exhaust inlet and outlet and the exhaust temperature difference are used to obtain the second power adjustment coefficient. To avoid damage to the fan for the incoming fresh air, the pressure difference of the preheating module is negatively correlated with the second power adjustment coefficient. Considering that the larger the temperature difference of the preheating module's exhaust, the stronger the heat exchange capacity of the preheating module, the fan power of the preheating module can be increased, the flow rate of the incoming fresh air can be increased, the heat in the working fluid can be avoided, and the overall waste heat utilization rate can be improved. Therefore, the temperature difference of the preheating module's exhaust is positively correlated with the first power adjustment coefficient.

[0105] Based on the current preheating fan power and the second power adjustment coefficient, the adjusted target power of the preheating fan is obtained; both the preheating fan power and the second power adjustment coefficient are positively correlated with the target power of the preheating fan.

[0106] As an example, the formula for calculating the target power of the preheating fan includes:

[0107]

[0108] Among them, P w_2 P represents the target power of the preheating fan after the current adjustment. w_2,t This indicates the current power of the preheating fan; Represents the second power regulation coefficient; norm() represents the linear normalization function; ΔT 17,18 Indicates the temperature rise of the fresh air entering the well; Y 17,18 This represents the air pressure difference of the preheating module; f() is used to... Positive correlation is mapped to -1 to 1.

[0109] The calculation formula for the target power of the preheating fan is similar to that for the exhaust fan. First, calculate Y... 17，18 Perform negative correlation mapping and then normalize; use the f() function to... The positive correlation is mapped to -1 to 1, which allows the second power regulation coefficient to increase or decrease the fan power.

[0110] It should be noted that, considering the need for a certain amount of time to switch the working mode after adjusting the waste heat deep utilization device, and to avoid interference from the previous working mode on the collected data, a minimum adjustment interval is set, such as 5 minutes. Within 5 minutes after each adjustment, no further adjustment judgment or adjustment of the water pump power and fan power is performed. After obtaining the adjusted target, the current power data and the adjusted power data are input using the PID control algorithm, and the parameters of the waste heat deep utilization device of the mine ventilation are adjusted by the PID control algorithm. The PID control algorithm is existing technology and will not be described in detail here.

[0111] Heating module control module 104: Used to monitor the working fluid temperature at the inlet of the preheating module and control the start and stop of the heating module.

[0112] Considering that the working fluid temperature at the inlet of the preheating module plays a decisive role in the preheating of the fresh air entering the well, if the working fluid temperature at the inlet of the preheating module is too low, it will not be able to play a preheating role. Therefore, the working fluid temperature at the inlet of the preheating module is monitored to control the start and stop of the heating module 19, so as to avoid the ventilation system from freezing.

[0113] Preferably, in one embodiment of the present invention, considering that the working fluid temperature at the working fluid inlet of the preheating module is continuously low and cannot preheat the incoming fresh air, the heating module 19 is started when the working fluid temperature at the working fluid inlet of the preheating module is lower than the preset minimum temperature threshold for a duration exceeding the preset time domain length, and the heating module 19 is turned off when the working fluid temperature at the working fluid inlet of the preheating module is higher than the preset minimum temperature threshold for a duration exceeding the preset time domain length.

[0114] As an example, the preset minimum temperature threshold is 2 degrees Celsius, and the preset time domain length is 5 minutes.

[0115] It should be noted that, to prevent the temperature of the incoming fresh air from being too high, heating can be paused when the temperature at the air outlet of 17 reaches 19.9 degrees Celsius. At the same time, additional encapsulation should be performed on the heating device according to the characteristics of the working medium. For example, when the water working medium is replaced with an ethylene glycol solution, a protective ceramic sleeve can be encapsulated on the outside of the heating rod of the heating module 19. A certain gap is left between the ceramic sleeve and the heating rod, which can be filled with water or air to prevent the heating rod from directly contacting the working medium.

[0116] This invention also proposes a method for deep utilization of waste heat from mine exhaust ventilation. This method utilizes an embodiment of the waste heat utilization device for mine exhaust ventilation described above. During waste heat utilization, workers install the device at the mine's ventilation system and activate the waste heat utilization control system. The control system automatically and continuously adjusts the water pump, fan, and heating module 19 based on collected data or processing results fed back from cloud computing. The entire process requires no manual intervention, improving the final utilization rate of waste heat from mine exhaust ventilation and preventing icing of the ventilation system.

[0117] In summary, addressing the technical problems of insufficient utilization of exhaust waste heat and the risk of icing in existing mine exhaust waste heat utilization devices, this invention proposes a device and method for deep utilization of mine exhaust waste heat. This invention collects mine exhaust waste heat using a working fluid in a waste heat collection module containing baffles 20. The working fluid is then transferred to a preheating module containing a heating module 19 to preheat the incoming fresh air. A waste heat utilization control system collects the working fluid temperature, exhaust air temperature, and air pressure difference at the inlet and outlet of the waste heat collection module and the preheating module. This analysis obtains effective waste heat utilization parameters, adjusts the water pump power and fan power, and monitors the working fluid temperature at the inlet of the preheating module to control the start and stop of the heating module 19.

[0118] It should be noted that the order of the above embodiments of the present invention is merely for descriptive purposes and does not represent the superiority or inferiority of the embodiments. The processes depicted in the accompanying drawings do not necessarily require a specific or sequential order to achieve the desired result. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0119] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

Claims

1. A device for deep utilization of waste heat from mine ventilation, characterized in that, The device is used to collect waste heat from mine exhaust air in a waste heat collection module containing baffles by means of a working fluid, and to transfer the working fluid to a preheating module containing a heating module to preheat the incoming fresh air; it also includes a waste heat utilization control system. The waste heat recovery control system includes: Data acquisition module: used to acquire the working fluid temperature, exhaust air temperature and air pressure difference at the inlet and outlet of the waste heat collection module and the preheating module; Waste heat utilization assessment module: used to obtain effective waste heat utilization parameters based on the relative change between the exhaust temperature and the working fluid temperature of the waste heat collection module, combined with the relative change between the exhaust temperature and the working fluid temperature of the preheating module, and the transmission loss of the working fluid. Waste heat utilization adjustment module: used to adjust the water pump power based on the overall working fluid temperature difference between the waste heat collection module and the preheating module, combined with the waste heat effective utilization parameters and the transmission loss of the working fluid; when adjusting the water pump power, the fan power is adjusted based on the waste heat effective utilization parameters, combined with the change of the exhaust temperature and the air pressure difference. Heating module control module: used to monitor the working fluid temperature at the inlet of the preheating module and control the start and stop of the heating module; The method for adjusting the water pump power includes: Based on the difference between the overall working fluid temperature of the waste heat collection module and the overall working fluid temperature of the preheating module, and in conjunction with the transmission loss, the module temperature difference parameter is obtained; the module temperature difference parameter and the waste heat effective utilization parameter are fused to obtain the adaptation coefficient of the device's operating parameters. When the adaptation coefficient is less than the preset adaptation threshold, it is determined to adjust the water pump power: based on the current water pump power and the module temperature difference parameter, the adjusted target water pump power is obtained; By integrating the pressure difference between the exhaust inlet and outlet of the waste heat collection module and the temperature difference of the exhaust air, a first power adjustment coefficient is obtained; based on the current exhaust fan power and the first power adjustment coefficient, the adjusted target power of the exhaust fan is obtained. The second power adjustment coefficient is obtained by combining the pressure difference between the air inlet and outlet of the preheating module and the temperature difference between the exhaust air. The adjusted target power of the preheating fan is obtained based on the current power of the preheating fan and the second power adjustment coefficient.

2. The device for deep utilization of waste heat from mine ventilation according to claim 1, characterized in that, The method for obtaining the parameters for effective waste heat utilization includes: The exhaust waste heat loss rate is obtained based on the relative change between the exhaust air temperature and the working fluid temperature of the waste heat collection module. The waste heat utilization rate of the exhaust is obtained based on the relative change between the exhaust temperature and the working fluid temperature of the preheating module. By integrating the exhaust waste heat loss rate, the exhaust waste heat utilization rate, and the transmission loss of the working fluid, effective waste heat utilization parameters are obtained; the exhaust waste heat utilization rate is positively correlated with the effective waste heat utilization parameters; both the exhaust waste heat loss rate and the transmission loss of the working fluid are negatively correlated with the effective waste heat utilization parameters.

3. The device for deep utilization of waste heat from mine ventilation according to claim 2, characterized in that, The method for obtaining the exhaust waste heat loss rate includes: The cooling rate of the mine exhaust is obtained based on the temperature difference between the exhaust inlet and outlet of the waste heat collection module; the heating rate of the working fluid is obtained based on the temperature difference between the working fluid inlet and outlet of the waste heat collection module; and the exhaust waste heat loss is obtained based on the difference between the cooling rate of the mine exhaust and the heating rate of the working fluid. The exhaust waste heat loss rate is obtained based on the ratio between the exhaust temperature at the exhaust inlet of the waste heat collection module and the exhaust waste heat loss amplitude; the exhaust waste heat loss amplitude is positively correlated with the exhaust waste heat loss rate; the exhaust temperature at the exhaust inlet of the waste heat collection module is negatively correlated with the exhaust waste heat loss rate.

4. A device for deep utilization of waste heat from mine ventilation according to claim 2, characterized in that, The method for obtaining the waste heat utilization rate of the exhaust air includes: The preheating range of the incoming fresh air is obtained based on the difference in exhaust air temperature between the fresh air inlet and the fresh air outlet of the preheating module; the cooling range of the working fluid is obtained based on the difference in working fluid temperature between the working fluid inlet and the working fluid outlet of the preheating module; and the waste heat loss range of the working fluid is obtained based on the difference between the preheating range of the incoming fresh air and the cooling range of the working fluid. The exhaust waste heat utilization rate is obtained based on the ratio of the working fluid temperature at the working fluid inlet of the preheating module to the magnitude of the working fluid waste heat loss; the magnitude of the working fluid waste heat loss is negatively correlated with the exhaust waste heat utilization rate; the working fluid temperature at the working fluid inlet of the preheating module is positively correlated with the exhaust waste heat utilization rate.

5. A device for deep utilization of waste heat from mine ventilation according to claim 1, characterized in that, The method for obtaining the transmission loss includes: The transmission loss is obtained based on the difference between the working fluid temperature at the working fluid outlet of the waste heat collection module and the working fluid temperature at the working fluid inlet of the preheating module.

6. A device for deep utilization of waste heat from mine ventilation according to claim 1, characterized in that, The method for controlling the start and stop of the heating module by monitoring the working fluid temperature at the inlet of the preheating module includes: When the working fluid temperature at the working fluid inlet of the preheating module is lower than the preset minimum temperature threshold for a duration exceeding a preset time range, the heating module is started, and the heating module is turned off when the working fluid temperature at the working fluid inlet of the preheating module is higher than the preset minimum temperature threshold for a duration exceeding the preset time range.

7. A device for deep utilization of waste heat from mine ventilation according to claim 1, characterized in that, The PID control algorithm is used when adjusting the power of the water pump and the power of the fan.

8. A method for deep utilization of waste heat from mine ventilation, characterized in that, The method utilizes a waste heat utilization device for mine exhaust as described in any one of claims 1 to 7 to utilize the waste heat of mine exhaust.

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