A coal pore structure active modification system and method based on steam operation working condition low-frequency alternating fatigue stress

Abstract

The application discloses a coal pore structure active modification system and method based on low-frequency alternating fatigue stress in a steam transportation working condition, which comprises a low-frequency vibration excitation unit and a control module, wherein the low-frequency vibration excitation unit is arranged at the lower edge of the bottom plate and the side baffle of a coal carriage, and is used for providing low-frequency vibration to expand coal particle fissures, penetrate through closed pores of the coal, and make organic matter and mineral interfaces debonded; the control module is communicatively connected with the low-frequency vibration excitation unit, and is used for controlling the low-frequency vibration excitation unit to realize an alternating cycle of periodic stress loading and static relaxation. The system and the method realize coal particle pore topology reconstruction by using the steam transportation and storage process of the coal, do not need external energy consumption and fixed equipment in a factory, can directionally reconstruct the multi-stage connected pore topology structure of the coal particles, and further improve the fixed carbon burnout rate and the boiler combustion efficiency.

Description

Technical Field

[0001] This invention relates to the field of energy-saving technology, and in particular to a system and method for actively modifying the pore structure of coal based on low-frequency alternating fatigue stress under road transport conditions. Background Technology

[0002] Coal combustion efficiency and burnout characteristics are mainly controlled by the microscopic pore structure of coal particles, pore connectivity, and the morphology of pyrolysis semi-coke. Mainstream thermal coals such as high-inert bituminous coal, lean coal, and anthracite generally have microscopic structural defects. For example, the inert aromatic carbon skeleton is dense and rigid, and the primary pores are mainly isolated micropores and closed dead pores. Embedded minerals such as clay, quartz, and pyrite easily block the pore channels, resulting in hindered volatile matter release during pyrolysis, easy collapse and closure of semi-coke pores, limited internal diffusion and mass transfer of oxygen during combustion, and multiphase oxidation reactions only occurring on the particle surface, with the internal carbon matrix unable to fully participate in the reaction. Ultimately, this leads to problems such as high carbon content in fly ash, boiler thermal efficiency loss, and poor combustion dynamic stability.

[0003] To improve combustion efficiency, coal needs to be upgraded and modified. Existing coal upgrading and modification technologies mainly fall into four categories: mechanical particle size reduction, thermal impact modification, chemical dissolution modification, and external force field modification. However, mechanical particle size reduction, achieved through mechanical grinding, only increases the surface area of ​​particles and cannot improve the internal closed pore structure. Furthermore, it suffers from high power consumption during pulverization and difficulty in particle size control. Thermal impact modification and chemical dissolution modification rely on high-energy external inputs and complex processes, resulting in high energy costs, uncontrollable coal quality damage, and poor on-site adaptability. Existing external force field modification primarily involves vibration modification, but it mainly focuses on improving the permeability and desorption of underground coal seam gas and preventing sticking and freezing during vehicle unloading. Its technical purpose is macroscopic material processing, and it has not yet formed a systematic modification system based on fatigue damage mechanics, directional control of coal micropore topology, and optimization of combustion kinetics. Summary of the Invention

[0004] To address some or all of the problems in existing technologies, and in order to achieve low-energy consumption, site-independent, and mechanism-controllable fuel quality improvement and efficiency enhancement, the first aspect of this invention provides an active coal pore structure modification system based on low-frequency alternating fatigue stress under road transport conditions, comprising: The low-frequency vibration excitation unit is installed at the bottom plate and the lower edge of the side baffle of the coal car body to provide low-frequency vibration, so as to expand the cracks of coal particles, open the closed pores of coal, and de-adhere the organic matter and mineral interface. A control module, which is communicatively connected to the low-frequency vibration excitation unit, is used to control the low-frequency vibration excitation unit to achieve alternating cycles of periodic stress loading and static relaxation.

[0005] Furthermore, the low-frequency vibration excitation unit includes a DC electromagnetic vibrator array, and the control module includes a PLC programmable timing controller, wherein the PLC programmable timing controller is used to provide intermittent start-stop and duty cycle adjustable cyclic excitation for the DC electromagnetic vibrator array.

[0006] Furthermore, the low-frequency vibration excitation unit includes a low-frequency eccentric vibration motor, and the control module includes a timing switch module, wherein the timing switch module is used to control the low-frequency eccentric vibration motor to start and stop intermittently, thereby realizing intermittent vibration and relaxation cycles.

[0007] Furthermore, the low-frequency vibration excitation unit includes an air storage component and a pulse pneumatic vibrator.

[0008] Furthermore, the active modification system for coal pore structure also includes: The sensing unit is communicatively connected to the control module and is used to collect the vibration spectrum of the coal car. Based on the vibration spectrum, the control module dynamically adjusts the vibration frequency, amplitude, and intermittent period of the low-frequency vibration excitation unit.

[0009] Furthermore, the active modification system for coal pore structure also includes: A vibration damping and isolation assembly is disposed between the low-frequency vibration excitation unit and the body of the coal transport car.

[0010] Based on the aforementioned active coal pore structure modification system, a second aspect of this invention provides a method for active modification of coal pore structure based on low-frequency alternating fatigue stress under road transport conditions, comprising: Raw coal is loaded into a coal transport car, wherein the loading thickness of the raw coal does not exceed a specified range; After the vehicle has been driving smoothly, the low-frequency vibration excitation unit is controlled to perform a cycle of periodic stress loading and static relaxation.

[0011] Furthermore, the active modification method for coal pore structure also includes: Before loading, an anti-sticking lining is installed inside the coal car body to prevent particle slippage and segregation.

[0012] Furthermore, the active modification method for coal pore structure also includes: After loading, a flexible sealing barrier is installed on the surface of the raw coal to prevent the escape of fine dust.

[0013] Furthermore, the active modification method for coal pore structure also includes: After turning off the low-frequency vibration excitation unit and letting it stand for a specified period of time, unload the material.

[0014] This invention provides a system and method for actively modifying the pore structure of coal based on low-frequency alternating fatigue stress during road transport. The system induces microscopic fatigue damage in the coal body using low-frequency alternating stress, and ensures stable pore reconstruction through an intermittent relaxation mechanism. The system and method rely entirely on the idle time during the entire coal transport process to complete the pre-modification of microstructures, requiring no pre-treatment equipment in the plant, generating no additional energy consumption, and occupying no production space. It is a green upgrading process coupled with storage and transportation conditions. The system supports multiple incentive implementation schemes, including electromagnetic, mechanical, pneumatic, and road condition adaptive composite schemes, adaptable to different transport conditions, coal types, and fleet modification needs. It balances low-cost, simple modification with intelligent adaptive control, possessing excellent engineering adaptability and industrialization advantages. Furthermore, the system and method are applicable to a wide range of coal types, showing significant upgrading effects on conventional bituminous coal, high-inert lean coal, and dense anthracite, and are particularly suitable for optimizing the combustion performance of low-activity, high-density, and difficult-to-burn coals. The coal modified by the system and method described above can optimize the pyrolysis and combustion kinetics, release volatiles more uniformly, and form a stable honeycomb porous structure in the semi-coke generated by pyrolysis, thereby reducing the activation energy of fixed carbon oxidation, increasing the multiphase combustion reaction rate, and effectively reducing the heat loss from incomplete combustion. Attached Figure Description

[0015] To further illustrate the above and other advantages and features of the various embodiments of the present invention, a more specific description of the various embodiments of the present invention will be presented with reference to the accompanying drawings. It is to be understood that these drawings depict only typical embodiments of the invention and are therefore not intended to limit its scope. In the drawings, identical or corresponding parts will be indicated by identical or similar reference numerals for clarity.

[0016] Figure 1 This diagram illustrates a structural schematic of an active coal pore structure modification system based on low-frequency alternating fatigue stress under road transport conditions, according to an embodiment of the present invention. Figure 2 This diagram illustrates a process flow chart of an active modification method for coal pore structure based on low-frequency alternating fatigue stress under road transport conditions, according to an embodiment of the present invention. Figure 3 This diagram illustrates a comparison of the microscopic crack structure of coal particles before and after modification using an active modification method for coal pore structure based on low-frequency alternating fatigue stress under transportation conditions, according to an embodiment of the present invention. Detailed Implementation

[0017] In the following description, the invention is described with reference to various embodiments. However, those skilled in the art will recognize that the embodiments may be practiced without one or more specific details or with other alternatives and / or additional methods, materials, or components. In other instances, well-known structures, materials, or operations are not shown or described in detail so as not to obscure the inventive points of the invention. Similarly, for illustrative purposes, specific quantities, materials, and configurations are set forth to provide a comprehensive understanding of embodiments of the invention. However, the invention is not limited to these specific details. Furthermore, it should be understood that the embodiments shown in the drawings are illustrative representations and are not necessarily drawn to scale.

[0018] In this specification, references to "an embodiment" or "this embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the invention. The phrase "in one embodiment" appearing throughout this specification does not necessarily refer to the same embodiment in all instances.

[0019] It should be noted that the embodiments of the present invention describe the process steps in a specific order; however, this is only for illustrating the specific embodiment and not for limiting the order of the steps. On the contrary, in different embodiments of the present invention, the order of the steps can be adjusted according to the process.

[0020] To address the industry bottlenecks of pore blockage, mineral clogging, high combustion mass transfer resistance, and low fixed carbon burnout rate in high-inert thermal coal, while avoiding additional energy consumption and production site occupation, this invention provides an active coal pore structure modification system based on low-frequency alternating fatigue stress during truck transportation. Utilizing the idle periods of coal transportation, it optimizes the pore topology of coal particles through non-destructive alternating stress accumulation damage, enhancing coal combustion reactivity from a mass transfer kinetics perspective. This results in low-energy consumption, site-independent, and mechanistically controllable fuel quality improvement and efficiency enhancement.

[0021] The modification principle of this invention is based on the theory of mismatch in multi-component media mechanics and the fatigue pore evolution law of porous media. The coal body is a heterogeneous composite medium composed of organic aromatic carbon skeleton, clay minerals, quartz, and pyrite. The elastic modulus, Poisson's ratio, and deformation response characteristics of each component are significantly different. Under the continuous action of low-frequency intermittent alternating vibration stress, a periodic alternating strain field is generated inside the coal body, and stress concentration effect occurs at the fracture tip and interphase interface, triggering three types of microstructure evolution behavior. First, the original microcracks undergo subcritical expansion under cyclic stress, and the fracture length, aperture, and connectivity continuously increase. Second, the walls of closed micropores undergo micro-fatigue cracking, and isolated dead pores connect with the fracture network to form a multi-level scale connected pore system. Finally, the interface of organic matter and inorganic mineral embedding undergoes gradual debonding and dissociation, eliminating the blocking effect of mineral particles on pore channels. Based on this, the present invention employs a differentiated control strategy of low-frequency, low-amplitude, and intermittent cyclic excitation, which differs from traditional high-frequency crushing vibration and continuous strong vibration compaction processes. This completely avoids the problems of macroscopic particle crushing, gradation deterioration, and secondary compaction of pores caused by high-energy vibration, inducing only microscopic controllable fatigue damage to the coal body. Furthermore, based on existing research in porous media mechanics and coal vibration response, it is known that coal bodies possess an inherent low-frequency resonance response range. Low-frequency alternating stress can precisely amplify the stress concentration effect at the fracture tip, promoting the steady-state expansion of subcritical fractures. Meanwhile, the vibration and relaxation intermittent mechanism can effectively release the accumulated compressive stress of particles, preventing pore closure and compaction. After modification, the tortuosity of coal particles is significantly reduced, and the effective interconnected porosity is greatly increased. The kinetic resistance to volatile matter release during pyrolysis is reduced, generating a thin-walled, porous, and highly interconnected honeycomb semi-coke structure. This significantly improves the internal diffusion mass transfer efficiency of oxygen during combustion, increases the rate constant of the fixed carbon multiphase oxidation reaction, and greatly enhances combustion completeness.

[0022] Based on the aforementioned principles, this invention constructs a low-frequency intermittent vibration realization system that is adaptable to road transport conditions, has multiple switchable modes, and is controllable and stable in operation. It can realize the target alternating stress field through various hardware topologies and control logics, is not limited to a single device, and is adaptable to various coal transport fleets and transportation scenarios. The specific technical implementation scheme includes multiple types of implementation forms that can be used independently or in combination.

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings of the embodiments.

[0024] Figure 1 This diagram illustrates a structural schematic of an active coal pore structure modification system based on low-frequency alternating fatigue stress under road transport conditions, according to an embodiment of the present invention. Figure 1As shown, an active modification system for coal pore structure based on low-frequency alternating fatigue stress under transportation conditions includes a low-frequency vibration excitation unit 101 and a control module (not shown). The low-frequency vibration excitation unit 101 is installed at the bottom plate and lower edge of the side baffles of the coal transport car 001. It provides low-frequency vibration to expand coal particle cracks, open closed pores in the coal, and de-adhede organic matter and mineral interfaces based on the aforementioned principle. The control module is communicatively connected to the low-frequency vibration excitation unit 101 and is used to control the low-frequency vibration excitation unit to achieve alternating cycles of periodic stress loading and static relaxation.

[0025] In one embodiment of the present invention, the low-frequency vibration excitation unit 101 includes a plurality of units, which are evenly arranged on the bottom plate and the lower edge of the side baffle of the coal car body 001, and may include one or more different implementation methods.

[0026] In one embodiment of the present invention, the low-frequency vibration excitation unit 101 includes a DC electromagnetic vibrator array, which generates stable low-frequency sinusoidal vibration excitation based on the principle of electromagnetic excitation alternation. It has no mechanical eccentric wear and the vibration frequency and amplitude are infinitely adjustable. In this embodiment, the control module includes a PLC programmable timing controller, which is used to provide intermittent start and stop, duty cycle adjustable cyclic excitation for the DC electromagnetic vibrator array. The output waveform is uniform and the stress loading is stable, which is suitable for various long-term road transport conditions. It can accurately match the steady-state alternating load required for the subcritical expansion of micro-fractures in coal, and is a preferred implementation method for high-precision modification.

[0027] In another embodiment of the present invention, the low-frequency vibration excitation unit 101 includes a low-frequency eccentric vibration motor, which generates low-frequency periodic excitation force by rotating an eccentric block. It features a simple structure, high reliability, and adaptability to complex road conditions in vehicles. In this embodiment, the control module includes a timing switch module, which controls the intermittent start and stop of the low-frequency eccentric vibration motor to achieve intermittent vibration and relaxation cycles. By locking the low-frequency excitation characteristics within a fixed speed range, it avoids high-frequency breakage effects, resulting in low cost and suitability for large-scale fleet vehicle upgrades.

[0028] In another embodiment of the present invention, the low-frequency vibration excitation unit 101 includes a gas storage component and a pulsed pneumatic vibrator, which generates low-frequency pulsed alternating impact stress, and the vibration waveform conforms to the optimal load characteristics of coal fatigue damage. Pulsed excitation has the characteristics of instantaneous stress concentration and short duration, which can enhance the crack tip propagation effect, while minimizing particle compaction and caking, making it suitable for modification scenarios of high-moisture and easily agglomerated raw coal.

[0029] It should be understood that, in some embodiments of the present invention, the low-frequency vibration excitation unit 101 may simultaneously include one or more components as described above, such as simultaneously including a DC electromagnetic vibrator array and a low-frequency eccentric vibration motor, or simultaneously including a low-frequency eccentric vibration motor and a pulse pneumatic vibrator, or simultaneously including a DC electromagnetic vibrator array, a low-frequency eccentric vibration motor and a pulse pneumatic vibrator, etc.

[0030] Furthermore, in order to achieve road condition cooperative adaptation, in one embodiment of the present invention, the active modification system for coal pore structure further includes a sensing unit 102, which is disposed, for example, at the bottom of the coal transport car and communicatively connected to the control module. The sensing unit 102 is used to collect the vibration spectrum of the coal transport car. Based on the vibration spectrum, the control module dynamically adjusts the vibration frequency, amplitude, and intermittent period of the low-frequency vibration excitation unit to achieve spectral coupling between active excitation and passive road condition vibration, enhance fatigue damage accumulation efficiency, make full use of the inherent vibration energy of the transportation conditions, and reduce the energy consumption of on-board equipment.

[0031] All of the aforementioned implementation schemes follow a unified modification logic, namely, inducing micro-fatigue damage in the coal body with low-frequency alternating stress, ensuring stable pore reconstruction with intermittent relaxation mechanism, not relying on a single equipment structure, and can be adaptively selected and combined according to transportation scenarios and coal characteristics.

[0032] In order to cut off the transmission of vibration energy to the chassis and suspension structure, and to achieve directional stress excitation of coal and zero-damage vibration isolation of the vehicle body, in one embodiment of the present invention, a vibration damping and isolation component 103 is also provided between the low-frequency vibration excitation unit 101 and the coal transport car 001. The vibration damping and isolation component 103 is made of, for example, high-damping rubber.

[0033] Based on the aforementioned active modification system for coal pore structure Figure 2 This diagram illustrates a process flow chart of an active modification method for coal pore structure based on low-frequency alternating fatigue stress under road transport conditions, according to an embodiment of the present invention. Figure 2 As shown, a method for actively modifying the pore structure of coal based on low-frequency alternating fatigue stress under truck transportation conditions includes: First, in step 201, an active modification system for the pore structure of coal is deployed. Low-frequency vibration excitation units are evenly distributed along the lower edge of the bottom plate and side baffles of the dump truck body, and connected to a control module. As mentioned above, in one embodiment of the present invention, a high-damping rubber vibration isolation structure can be set between the low-frequency vibration excitation unit and the truck body to cut off the transmission of vibration energy to the chassis and suspension structure, thereby achieving directional stress excitation of coal and zero-damage vibration isolation of the truck body. Next, in step 202, raw coal is loaded. Raw coal 002 is loaded into the coal transport car, wherein the loading thickness of the raw coal does not exceed a specified range. The loading of raw coal is completed according to conventional storage and transportation processes, while controlling the thickness of the material layer in the car. The contact constraint effect between particles in the thick material layer is used to suppress macroscopic particle bouncing, ensuring that alternating stress is uniformly transferred to the internal coal particles, achieving homogeneous modification of the entire microstructure. In one embodiment of the invention, to suppress particle slippage and segregation, a low-friction anti-sticking lining 104 is provided on the inner side of the coal transport car before loading. In another embodiment of the invention, to suppress the emission of fine dust, a flexible sealing barrier structure 105 is covered on the surface of the raw coal after loading. Next, in step 203, low-frequency intermittent vibration modification is performed. After the vehicle has stabilized, the low-frequency vibration excitation unit is controlled to perform alternating cycles of periodic stress loading and static relaxation. After the vehicle has stabilized, the low-frequency vibration excitation unit is activated, and an adaptive low-frequency intermittent alternating stress field is constructed through the control module. This supports adaptive switching of multiple standardized excitation modes. Through the alternating cycles of periodic stress loading and static relaxation, micro-fatigue damage to the coal body is continuously accumulated throughout the entire transportation time, progressively completing the full-domain modification of the microstructure, including coal particle fracture expansion, closed pore connection, and debonding of organic matter and mineral interfaces. As mentioned above, the low-frequency intermittent vibration modification can be achieved through one or more of the following: distributed electromagnetic low-frequency intermittent vibration excitation, eccentric mechanical low-frequency intermittent vibration excitation, pneumatic low-frequency pulse intermittent vibration excitation, and road condition-coordinated adaptive composite vibration.

[0034] In one embodiment of the present invention, the vibration excitation is terminated before the vehicle arrives at the unloading area, and the material is unloaded after a specified period of time. This allows the micro-stress inside the coal body to relax and the particle packing structure to return to stability, thus avoiding fine powder enrichment and particle size segregation during the unloading process.

[0035] As mentioned above, in the embodiments of the present invention, different low-frequency intermittent vibration modification schemes can be selected according to different working conditions: For example, for short-distance truck transport within the factory and within the same city, with a transport time of no more than 4 hours, a DC electromagnetic low-frequency alternating stress exciter array can be selected. This array relies on the vehicle's original battery for power generation throughout the journey. The truck bed is equipped with a high-damping vibration-damping isolation structure and sealed enclosures. Conventional bituminous coal is loaded, and a reasonable stacking thickness is controlled. Adapting to the characteristics of insufficient short-term fatigue accumulation, a high-frequency, low-amplitude, high-density intermittent alternating stress excitation mode is adopted, with stress relaxation before unloading. Microscopic testing shows that this operating condition can effectively open up shallow, closed micropores in the coal body, eliminate surface blockage defects in minerals, and significantly improve pore connectivity. Under combustion conditions, the uniformity of volatile matter release is improved, furnace temperature fluctuations are reduced, fly ash carbon content is lowered, equipment operation is stable, and there is no dust spillage or vehicle body damage.

[0036] For cross-city regular freight transport, with a transit time of 4 to 10 hours, a vehicle-mounted low-frequency eccentric alternating stress excitation motor can be selected, operating continuously with the original vehicle's DC power supply, loaded with high-inert lean coal (a representative of difficult-to-burn coal types). Medium-range standard equilibrium intermittent alternating stress excitation parameters are used, with standard stress loading and relaxation cycles, lasting 6 to 8 hours in total. This condition matches the optimal steady-state range of coal micro-fatigue, resulting in densely developed fracture networks, interconnected deep pores, and significant debonding effects at mineral interfaces; the modified semi-coke exhibits a complete honeycomb structure and a substantial reduction in oxygen mass transfer resistance.

[0037] For long-distance inter-provincial freight transport, with a transport time of 10 hours or more, a dual-backup power supply solution combining pneumatic low-frequency pulse alternating stress excitation equipment and independent parking lithium battery energy storage can be selected to adapt to ultra-long transport conditions. Loading low-activity dense anthracite, a robust excitation mode with a low-frequency long relaxation period is adopted to avoid the risk of particle compaction caused by long-term stress accumulation. Under ultra-long-term fatigue accumulation, the dense inert skeleton of the anthracite is fully decomposed, a multi-level interconnected pore system is formed, and the tortuosity of the pores is significantly reduced; the fixed carbon burnout rate is significantly improved after modification, the carbon content of fly ash is reduced, and the low-load stable combustion performance is greatly optimized, completely solving the problem of inefficient combustion of high-density anthracite.

[0038] Figure 3 This diagram illustrates a comparison of the microscopic fracture structure of coal particles before and after modification using a method based on low-frequency alternating fatigue stress under transportation conditions, according to an embodiment of the present invention. It can be seen that, through this method, the initial discontinuous fractures of the raw coal, initially diluted, are extended, developing into secondary cracks. Isolated main fractures are expanded, leading to the convergence and interconnection of fractures. Simple branching fractures are connected into a grid-like interconnected fracture network, and local short fracture clusters are extended, forming overlapping connections. Compared to unmodified coal of the same origin and under the same transportation conditions, after modification using the aforementioned method, the proportion of closed pores is reduced, the inert skeleton is looser, the pore channels are more tortuous, and mineral blockage is significantly improved. This prevents the formation of a dense, non-porous, rigid structure from pyrolysis semi-coke, which would severely restrict oxygen diffusion and mass transfer. The modified raw coal participates more in the oxidation reaction, resulting in complete combustion, low fly ash residual carbon, and high combustion kinetic stability. The modified raw coal can be fed into the coal conveying and blending system of a power plant, and its superior pore structure and pyrolysis characteristics after modification can be used to achieve efficient combustion.

[0039] Although various embodiments of the invention have been described above, it should be understood that they are presented by way of example only and not as limitations. It will be apparent to those skilled in the art that various combinations, modifications, and alterations can be made without departing from the spirit and scope of the invention. Therefore, the breadth and scope of the invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely by the appended claims and their equivalents.

Claims

1. A coal pore structure active modification system based on low-frequency alternating fatigue stress under road transport conditions, characterized in that, include: The low-frequency vibration excitation unit is installed at the bottom plate and the lower edge of the side baffle of the coal car body, and is configured to provide low-frequency vibration to expand the cracks of coal particles, open the closed pores of coal, and de-adhere the organic matter and mineral interface. A control module, which is communicatively connected to the low-frequency vibration excitation unit and configured to control the low-frequency vibration excitation unit to achieve alternating cycles of periodic stress loading and static relaxation.

2. The active coal pore structure modification system as described in claim 1, characterized in that, The low-frequency vibration excitation unit includes a DC electromagnetic vibrator array, and the control module includes a PLC programmable timing controller, wherein the PLC programmable timing controller is configured to provide intermittent start-stop, duty cycle adjustable cyclic excitation to the DC electromagnetic vibrator array.

3. The active coal pore structure modification system as described in claim 1, characterized in that, The low-frequency vibration excitation unit includes a low-frequency eccentric vibration motor, and the control module includes a timing switch module, wherein the timing switch module is configured to control the low-frequency eccentric vibration motor to start and stop intermittently, thereby realizing intermittent vibration and relaxation cycles.

4. The active coal pore structure modification system as described in claim 1, characterized in that, The low-frequency vibration excitation unit includes an air storage component and a pulse pneumatic vibrator.

5. The active coal pore structure modification system as described in claim 1, characterized in that, Also includes: A sensing unit is communicatively connected to the control module and configured to acquire the vibration spectrum of the coal car. The control module is configured to dynamically adjust the vibration frequency, amplitude, and intermittent period of the low-frequency vibration excitation unit based on the vibration spectrum.

6. The active coal pore structure modification system as described in claim 1, characterized in that, Also includes: A vibration damping and isolation assembly is disposed between the low-frequency vibration excitation unit and the body of the coal transport car.

7. A method for actively modifying the pore structure of coal based on low-frequency alternating fatigue stress under road transport conditions, characterized in that, Active modification of coal pore structure is performed using the active coal pore structure modification system as described in any one of claims 1 to 6, and includes: Raw coal is loaded into a coal transport car, wherein the loading thickness of the raw coal does not exceed a specified range; After the vehicle has been driving smoothly, the low-frequency vibration excitation unit is controlled to perform a cycle of periodic stress loading and static relaxation.

8. The method for actively modifying the pore structure of coal as described in claim 7, characterized in that, Also includes: Before loading, an anti-sticking lining is installed inside the coal car body to prevent particle slippage and segregation.

9. The method for actively modifying the pore structure of coal as described in claim 7, characterized in that, Also includes: After loading, a flexible sealing barrier is installed on the surface of the raw coal to prevent the escape of fine dust.

10. The method for actively modifying the pore structure of coal as described in claim 7, characterized in that, Also includes: After turning off the low-frequency vibration excitation unit and letting it stand for a specified period of time, unload the material.

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