Coal dust participates in two-phase synergistic exothermic oxidation low-concentration gas energy utilization device and control method

Abstract

The present application belongs to the technical field of coal mine gas control, mine ventilation safety and low concentration gas resource utilization, and particularly relates to a low concentration gas energy utilization device and control method with coal dust participating in two-phase synergistic oxidation and heat release, which solves the problem of low utilization efficiency of low concentration gas in coal mine at present. The device comprises a mobile chassis, an air inlet duct, a variable frequency speed regulation fan, a heat accumulating oxidation reactor, a ceramic heat accumulator, a coal dust quantitative supply unit, a heat exchanger, a tail gas discharge pipe, a gas concentration sensor, a temperature sensor and an intelligent control unit. The intelligent control unit collects gas concentration and reaction temperature, adjusts air inlet quantity, heat accumulating oxidation intensity and coal dust feeding state according to a preset hierarchical control strategy; when gas alone oxidation and heat release is insufficient, fine coal dust is introduced quantitatively, so that coal dust and gas form a gas-solid two-phase synergistic oxidation and heat release system in the heat accumulating oxidation reactor. The present application improves the oxidation stability and energy recovery efficiency of low concentration gas.

Description

Technical Field

[0001] This invention belongs to the technical field of coal mine gas control, mine ventilation safety and low-concentration gas resource utilization, specifically involving a low-concentration gas energy utilization device and control method that utilizes coal dust in two-phase synergistic oxidation and exothermic reaction. Background Technology

[0002] Coal mine production and ventilation processes generate large amounts of low-concentration methane gas. This gas typically has a low methane volume fraction, poor direct combustion stability, and significant calorific value fluctuations, making it difficult to utilize efficiently using conventional combustion methods. While existing regenerative thermal oxidation (RTO) devices can handle low-concentration methane to some extent, they still suffer from insufficient reactivity, difficulty in maintaining regenerative temperature, and low energy recovery efficiency when methane concentrations are low or fluctuate significantly.

[0003] A certain amount of coal dust is present in the underground working environment of coal mines. Coal dust poses safety risks under conditions of disordered accumulation and high-temperature ignition sources. However, if quantitatively introduced into a closed, monitorable, controlled, and interlocked reaction device, it can serve as an auxiliary exothermic medium in the controlled oxidation process, thereby compensating for insufficient heat release during the oxidation of low-concentration methane alone. Existing low-concentration methane utilization equipment typically focuses on single gas-phase oxidation or single waste heat recovery, lacking a technical solution that integrates quantitative coal dust supply, regenerative oxidation, waste heat recovery, and safety interlock control.

[0004] Therefore, there is an urgent need to provide a device and control method that can improve the oxidation stability and energy utilization efficiency of low-concentration methane under safety constraints. Summary of the Invention

[0005] The purpose of this invention is to provide a low-concentration gas energy utilization device and control method that utilizes coal dust in two-phase synergistic oxidation and exothermic reactions, in order to solve the problems of insufficient stability, limited exothermic intensity, and low waste heat utilization efficiency of existing low-concentration gas oxidation reactions.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a low-concentration gas energy utilization device and control method for coal dust participating in two-phase synergistic oxidation and exothermic reaction, comprising a mobile chassis, an air inlet duct, a variable frequency speed-regulating fan, a regenerative oxidation reactor, a ceramic heat storage body, a coal dust quantitative supply unit, a heat exchanger, a tail gas emission pipe, a gas concentration sensor, a temperature sensor, and an intelligent control unit. The variable frequency speed-regulating fan is used to introduce low-concentration gas airflow into the air inlet duct and regulate the airflow volume; the regenerative oxidation reactor is used to form a stable oxidation reaction zone; the ceramic heat storage body is used to accumulate and recover the reaction heat; the coal dust quantitative supply unit is used to quantitatively introduce fine coal dust particles into the reaction zone according to the control commands output by the intelligent control unit; the heat exchanger is used to recover the heat carried by the gas after the reaction; and the tail gas emission pipe is used to discharge the heat-exchanged tail gas.

[0007] The gas concentration sensor is used to collect the gas concentration at the air inlet in real time, and the temperature sensor is used to collect the temperature inside the regenerative oxidation reactor in real time. The intelligent control unit determines the system operating condition based on the gas concentration and reaction temperature, and performs linkage control on the variable frequency speed-regulating fan and the coal dust metering supply unit respectively, so that the system switches between low-concentration gas oxidation, regenerative oxidation, and gas-solid synergistic oxidation exothermic reaction.

[0008] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention adopts a method of coupling quantitative coal dust supply with low-concentration gas regenerative oxidation, thereby enhancing the thermal field of the oxidation reaction through coal dust combustion, which improves the reactivity of low-concentration gas while stabilizing its heat release process.

[0009] 2. This invention utilizes a combination of ceramic heat storage body and heat exchanger to divide the heat of reaction into two parts for utilization: the former maintains the self-sustaining reaction through heat storage-heat release cycle, while the latter realizes the recovery of external energy levels through heat exchange, thereby comprehensively improving energy utilization efficiency.

[0010] 3. This invention collects operating condition signals through a gas concentration sensor and a temperature sensor. The intelligent control unit adaptively adjusts the air intake and coal dust feed rate according to the operating condition signals to form a closed-loop control system, thereby achieving stable oxidation under varying operating conditions.

[0011] 4. This invention integrates multiple safety protection mechanisms such as feeding limit, abnormal supply stoppage, backflow prevention and alarm. By limiting the peak coal dust supply, blocking the high-temperature backflow path and rapid fault response, it effectively suppresses the potential causes of deflagration in the coal dust assisted oxidation process.

[0012] 5. The device of this invention is mounted on a mobile chassis and has the ability to be deployed across different areas underground, which can flexibly adapt to the needs of multi-point and dispersed gas control in coal mines. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of a low-concentration gas energy utilization device that utilizes coal dust in a two-phase synergistic oxidation process according to the present invention.

[0014] In the diagram: 1. Mobile chassis; 2. Air inlet duct; 3. Variable frequency speed control fan; 4. Regenerative oxidation reactor; 5. Ceramic heat storage body; 6. Coal dust metering supply unit; 7. Heat exchanger; 8. Exhaust gas emission pipe; 9. Gas concentration sensor; 10. Temperature sensor; 11. Intelligent control unit. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings. The described embodiments are only for explaining the present invention and are not intended to limit the scope of protection of the present invention. All equivalent substitutions, combinations or improvements made based on the concept of the present invention should fall within the scope of protection of the present invention.

[0016] like Figure 1 As shown, the low-concentration gas energy utilization device for coal dust participating in two-phase synergistic oxidation and exothermic reaction provided in this embodiment is installed on a mobile chassis (1). The mobile chassis (1) can be configured with track wheels, casters or track walking mechanisms according to the layout conditions of the mine roadway. The air intake duct (2) is fixedly installed on the mobile chassis (1), and the variable frequency speed regulating fan (3) is installed at the air intake end of the air intake duct (2) to introduce airflow containing low-concentration gas and regulate the air flow rate.

[0017] The regenerative oxidation reactor (4) is located in the airflow passage of the air inlet duct (2), and the regenerative oxidation reactor (4) is filled with ceramic heat storage body (5). During system operation, the ceramic heat storage body (5) absorbs and stores the heat released by the oxidation reaction and preheats the low-concentration gas flow that subsequently enters, so that the reaction zone can maintain a stable exothermic reaction state.

[0018] The coal dust metering supply unit (6) is connected to the regenerative thermal oxidation reactor (4). The coal dust metering supply unit (6) may include a coal dust storage bin, a metering feeding mechanism and an injection mechanism. The metering feeding mechanism adjusts the amount of fine coal dust particles fed according to the control instructions of the intelligent control unit (11). The injection mechanism uniformly feeds the coal dust particles into the reaction zone of the regenerative thermal oxidation reactor (4), so that the coal dust particles and the low-concentration gas flow form a gas-solid two-phase synergistic oxidation and exothermic system in a high-temperature regenerative environment.

[0019] The outlet end of the regenerative oxidation reactor (4) is connected to the heat exchanger (7). The heat exchanger (7) is a gas-water heat exchanger used to recover the heat from the high-temperature gas after the reaction. The exhaust gas after heat exchange is discharged through the exhaust gas discharge pipe (8), which is equipped with an anti-backflow structure to prevent the exhaust gas or external airflow from entering the reaction system in reverse.

[0020] A gas concentration sensor (9) is arranged in the air inlet or in the air inlet duct (2) to obtain the gas concentration in real time; a temperature sensor (10) is arranged in the regenerative oxidation reactor (4) to obtain the reaction temperature in real time. The intelligent control unit (11) receives the gas concentration and reaction temperature signals and outputs control commands to the variable frequency speed control fan (3) and the coal dust quantitative supply unit (6).

[0021] The control method of this embodiment includes the following process: After the system is started, the variable frequency speed control fan (3) introduces the low-concentration gas airflow into the air intake duct (2); the intelligent control unit (11) continuously reads the gas concentration and reaction temperature, and judges the current operating condition according to the preset control strategy. When the gas concentration is less than 0.3%, the system mainly uses basic ventilation and low-intensity oxidation; when the gas concentration is greater than or equal to 0.3% and less than 0.8%, the system relies on the ceramic heat storage body (5) to maintain the heat storage oxidation reaction; when the reaction temperature is lower than the preset maintenance temperature or when it is necessary to increase the heat output, the intelligent control unit (11) turns on the coal dust quantitative supply unit (6) and adjusts the coal dust feed rate according to the temperature deviation and safety limit.

[0022] During the gas-solid co-oxidation exothermic process, the intelligent control unit (11) continuously monitors the gas concentration, reaction temperature, and coal dust feeding status. When any parameter meets the preset abnormal conditions, the intelligent control unit (11) performs one or more of the following safety protection actions: stopping coal dust supply, reducing the speed of the variable frequency speed-regulating fan (3), starting the alarm, and maintaining unidirectional flow of exhaust gas, thereby preventing the system from entering the deflagration or explosion risk zone.

[0023] It should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the implementation of the invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should fall within the scope of the disclosed technical content. It should also be noted that in the description of this invention, terms such as "upper," "lower," "inner," "outer," "inlet," and "outlet" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are used solely for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Terms such as "first" and "second" are used only to distinguish related technical features and do not indicate or imply relative importance or implicitly specify the number of indicated technical features. Thus, features defined with "first" or "second" may explicitly or implicitly include one or more of the stated features.

[0024] Those skilled in the art can make appropriate adjustments or equivalent substitutions to the structural form, control parameters and connection methods in the above embodiments without departing from the technical concept of the present invention, and such adjustments or substitutions should all fall within the protection scope of the present invention.

Claims

1. A low-concentration gas energy utilization device that utilizes coal dust in a two-phase synergistic oxidation process, characterized in that, The system includes a mobile chassis (1), an air inlet duct (2), a variable frequency speed-regulating fan (3), a regenerative oxidation reactor (4), a ceramic heat storage body (5), a coal dust metering supply unit (6), a heat exchanger (7), a tail gas emission pipe (8), a gas concentration sensor (9), a temperature sensor (10), and an intelligent control unit (11). The air inlet duct (2) is mounted on the mobile chassis (1), the variable frequency speed-regulating fan (3) is mounted at the air inlet end of the air inlet duct (2), the regenerative oxidation reactor (4) is mounted on the airflow passage of the air inlet duct (2), and the ceramic heat storage body (5) is filled in the regenerative oxidation reactor. Inside the thermal oxidation reactor (4); the coal dust quantitative supply unit (6) is connected to the thermal oxidation reactor (4) and is used to quantitatively supply fine coal dust particles into the thermal oxidation reactor (4); the heat exchanger (7) is connected to the outlet end of the thermal oxidation reactor (4), and the tail gas discharge pipe (8) is connected to the tail gas outlet of the heat exchanger (7); the gas concentration sensor (9) and the temperature sensor (10) are electrically connected to the intelligent control unit (11), and the intelligent control unit (11) controls the operating status of the variable frequency speed regulating fan (3) and the coal dust quantitative supply unit (6).

2. The low-concentration gas energy utilization device for coal dust participating in two-phase synergistic oxidation and exothermic reaction according to claim 1, characterized in that, The ceramic heat storage body (5) in the regenerative oxidation reactor (4) is arranged along the airflow direction to store the heat released by the oxidation reaction and preheat the low-concentration gas flow entering the reaction zone in order to maintain the continuity of the enhanced oxidation reaction.

3. The low-concentration gas energy utilization device for coal dust participating in two-phase synergistic oxidation and exothermic reaction according to claim 1, characterized in that, The coal dust quantitative supply unit (6) includes a coal dust storage bin, a metering feeding mechanism and an injection mechanism. The metering feeding mechanism is used to adjust the feeding amount of fine coal dust particles, and the injection mechanism is used to uniformly feed the fine coal dust particles into the reaction zone of the regenerative oxidation reactor (4).

4. A low-concentration gas energy utilization device for coal dust participating in two-phase synergistic oxidation and exothermic reaction according to claim 3, characterized in that, The coal dust quantitative supply unit (6) is equipped with a start-stop interlock mechanism; when the gas concentration, reaction temperature or coal dust feeding status exceeds the preset safety limit, the start-stop interlock mechanism cuts off the coal dust supply.

5. A low-concentration gas energy utilization device for coal dust participating in two-phase synergistic oxidation and exothermic reaction according to claim 1, characterized in that, The heat exchanger (7) is a gas-water heat exchanger used to recover the heat carried by the outlet gas of the regenerative oxidation reactor (4) and supply heat to the external heat-using end.

6. The low-concentration gas energy utilization device for coal dust participating in two-phase synergistic oxidation and exothermic reaction according to claim 1, characterized in that, The exhaust pipe (8) is equipped with an anti-backflow structure, which is used to prevent exhaust gas or external airflow from entering the heat exchanger (7) and the regenerative oxidation reactor (4) in reverse.

7. A low-concentration gas energy utilization device for coal dust participating in two-phase synergistic oxidation and exothermic reaction according to claim 1, characterized in that, The mobile chassis (1) is equipped with track wheels, casters or track walking mechanisms at the bottom so that the device can be moved and arranged in the mine roadway.

8. A control method for a low-concentration gas energy utilization device in which coal dust participates in two-phase synergistic oxidation and exothermic reaction, characterized in that, Includes the following steps: S1. Real-time monitoring: The gas concentration at the air inlet is collected by the gas concentration sensor (9), and the reaction temperature inside the regenerative oxidation reactor (4) is collected by the temperature sensor (10). S2, Operating Condition Judgment: The intelligent control unit (11) judges the operating condition of the system based on the gas concentration and reaction temperature; S3, graded control: the intelligent control unit (11) adjusts the speed of the variable frequency speed regulating fan (3) according to the operating conditions, and controls the start and stop of the coal dust quantitative supply unit (6) and the amount of material fed; S4. Waste heat recovery: The high-temperature gas after the reaction enters the heat exchanger (7) for heat recovery and is discharged through the tail gas discharge pipe (8).

9. The control method for a low-concentration gas energy utilization device involving coal dust in two-phase synergistic oxidation and exothermic reaction according to claim 8, characterized in that, The graded control includes: when the gas concentration is less than 0.3%, the intelligent control unit (11) controls the system in basic ventilation and low-intensity oxidation mode; when the gas concentration is greater than or equal to 0.3% and less than 0.8%, the intelligent control unit (11) controls the system in heat storage and maintenance oxidation mode; when the reaction temperature is lower than the preset maintenance temperature or when it is necessary to increase the heat output, the intelligent control unit (11) controls the coal dust quantitative supply unit (6) to supply fine coal dust particles to the heat storage oxidation reactor (4) according to the preset ratio or closed-loop adjustment amount, so as to form a gas-solid synergistic oxidation exothermic mode.

10. The control method for a low-concentration gas energy utilization device involving coal dust in two-phase synergistic oxidation and exothermic reaction as described in claim 8, characterized in that, In the gas-solid synergistic oxidation exothermic mode, the intelligent control unit (11) adjusts the amount of coal dust feed according to the deviation between the reaction temperature and the target temperature range, and adjusts the speed of the variable frequency speed regulating fan (3) in conjunction with the adjustment, so that the regenerative oxidation reactor (4) is maintained in the preset oxidation exothermic zone.

11. A control method for a low-concentration gas energy utilization device involving coal dust participating in two-phase synergistic oxidation and exothermic reaction, as described in claim 9 or 10, characterized in that, When the gas concentration, reaction temperature or coal dust feed rate meets the preset abnormal conditions, the intelligent control unit (11) performs a safety protection action, which includes at least one of reducing the air intake, stopping the coal dust supply, activating the alarm, and maintaining unidirectional exhaust gas emission.

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