An intrinsically safe system and method for supplementing gas-fired ventilation and oxidation

Abstract

This invention discloses an intrinsically safe system and method for exhaust gas supplementary oxidation, comprising an energy storage system, an exhaust gas supply system, a valve group safety switching system, a regenerative preheating system, an intrinsically safe oxidation reaction system, a waste heat utilization system, and a monitoring and control system. It achieves multi-energy complementary supplementation through coupled solar thermal, photovoltaic, and wind power thermal / electrical storage modules. A three-stage temperature feedback control system is constructed, with the reactor inlet preheating temperature, catalytic oxidation reaction zone temperature, and outlet high-temperature gas temperature as the core. Combined with the confined space catalytic reactor and the "one-way isolation - main circuit cut-off - bypass venting" valve group interlocking, a five-fold intrinsically safe protection is formed. This invention can stably maintain low-temperature, flameless catalytic oxidation of exhaust gas under low-concentration and fluctuating operating conditions, while reducing the risks of thermal runaway, backfire, and pressure backflow. It achieves cascade utilization of waste heat and renewable energy consumption, and is applicable to the harmless treatment of coal mine exhaust gas and mine area energy supply scenarios.

Description

Technical Field

[0001] This invention belongs to the field of low-carbon utilization, catalytic oxidation, waste heat recovery, multi-energy complementary power supply and safety control technology of coal mine exhaust gas, specifically involving an intrinsically safe exhaust gas supplementary oxidation system and method. Background Technology

[0002] Exhaust gas from coal mine ventilation systems contains methane and is characterized by large air volume, low methane concentration (typically 0.1% to 1% by volume), significant concentration fluctuations, and low supply pressure. Due to its low methane concentration and low calorific value per unit volume, exhaust gas is difficult to utilize directly and stably using conventional combustion methods. For a long time, large quantities have been directly emitted, resulting in both greenhouse gas emissions and energy waste.

[0003] Currently, waste gas treatment and utilization technologies mainly include regenerative thermal oxidation, catalytic oxidation, and waste heat recovery. Regenerative thermal oxidation units typically rely on high bed temperatures to maintain methane oxidation, requiring significant start-up heat replenishment. Under low concentration or fluctuating concentration conditions, they are prone to problems such as difficulty in maintaining temperature, localized overheating, or insufficient energy utilization. Catalytic oxidation technology can lower the methane oxidation temperature, but under high flow rate and low concentration conditions, stable preheating and energy replenishment are still required to ensure the reactor remains in an effective catalytic state.

[0004] Existing waste gas oxidation systems primarily focus on single oxidation reactions or single waste heat recovery, lacking sufficient integration with multi-energy complementary supplementation methods such as solar thermal, photovoltaic, wind power, and thermal and electrical storage. Furthermore, there is insufficient coordinated control over the reactor inlet preheating temperature, reaction zone oxidation temperature, and outlet gas temperature, and the interlocking matching degree of inlet gas cutoff, bypass venting, and pressure isolation under abnormal operating conditions is not high. Insufficient energy supplementation can easily lead to reactor instability and flameout, while excessive energy supplementation or reheating can easily cause local overheating, increasing the safety risks of thermal runaway, backfire, or abnormal pressure propagation.

[0005] Therefore, there is an urgent need to develop a waste gas treatment system that integrates energy storage, regenerative preheating, low-temperature catalytic oxidation, waste heat utilization, and interlocking protection to achieve safe and stable oxidation of low-concentration waste gas in a confined space without open flame, at controlled temperature, and in a confined space, and to improve energy utilization efficiency. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing an intrinsically safe system and method for waste gas catalytic oxidation, which solves the problems of difficulty in starting and maintaining low-concentration waste gas catalytic oxidation, large temperature fluctuations, and insufficient safety control under abnormal operating conditions, thereby achieving multi-energy complementary energy replenishment, waste heat cascade utilization, and intrinsically safe control throughout the entire process.

[0007] To achieve the above objectives, the technical solution adopted by the present invention is: an intrinsically safe waste gas supplementary oxidation system, comprising a supplementary energy storage system, a waste gas supply system, a valve group safety switching system, a regenerative preheating system, an intrinsically safe oxidation reaction system, a waste heat utilization system, and a monitoring and control system.

[0008] The energy storage and replenishment system includes a solar thermal module, a photovoltaic module, a wind power module, and a thermal / electrical storage module. The solar thermal module converts solar energy into heat energy, while the photovoltaic and wind power modules convert solar and wind energy into electrical energy, respectively. All three energy sources are connected to the thermal / electrical storage module for storage, voltage stabilization, and distribution. The thermal / electrical storage module has three outputs: a system energy replenishment output for regenerator preheating and reactor start-up / maintenance heat replenishment; a system power output for supplying power to the gas extraction fan, regulating valve, shut-off valve, bypass valve, and monitoring and control system; and a user energy supply output to provide heat or electricity to users in the mining area. This system not only achieves renewable energy consumption but also buffers and smooths out fluctuations through energy storage, preventing energy input fluctuations from directly impacting the reactor. Furthermore, during the start-up phase, the thermal / electrical storage module prioritizes outputting replenishment heat energy to the regenerator and reactor. During stable operation, it primarily recovers heat from waste heat, supplemented by energy replenishment regulation. Under low-concentration fluctuation conditions, the replenishment power is dynamically adjusted based on real-time monitoring values ​​from various temperature detection points in the reactor.

[0009] The exhaust gas supply system includes an exhaust gas inlet, an intake fan, a pressure stabilizing device, a pressure gauge, a flow meter, and an electric regulating valve. After the exhaust gas is delivered by the intake fan, the pressure stabilizing device reduces airflow fluctuations. The pressure gauge and flow meter monitor the pipeline status in real time. The electric regulating valve is connected to the monitoring and control system and adjusts the intake gas volume based on temperature, pressure, and flow feedback to ensure stable gas supply.

[0010] The valve group safety switching system includes a check valve, a shut-off valve, a bypass valve, and a vent. The check valve is positioned between the electric regulating valve and the shut-off valve to prevent high-temperature gas and pressure waves from flowing back to the intake end. The shut-off valve controls the main pipeline's on / off state. The bypass valve connects the main intake pipeline to the vent, working in conjunction with the shut-off valve to achieve main / bypass switching. Under abnormal operating conditions, the shut-off valve closes and the bypass valve opens, allowing exhaust gas to be directly vented, thus preventing intake gas from entering the high-temperature reaction zone and avoiding pressure buildup in the upstream pipeline.

[0011] The regenerative preheating system includes a regenerator located between the main intake pipe and the reactor. It utilizes the waste heat from the reactor outlet exhaust gas to preheat the exhaust gas at the inlet, reducing the need for external energy replenishment. A reactor inlet preheating temperature detection point (temperature T1) is set between the regenerator outlet and the reactor inlet, serving as the core parameter for determining intake access.

[0012] The intrinsically safe oxidation reaction system includes a confined space reactor with an inert heat storage body, a low-temperature catalyst, and a high-temperature catalyst arranged along the airflow direction. The inert heat storage body absorbs, stores, and releases heat, and uniformly distributes the airflow and buffers the temperature. The low-temperature catalyst reduces the initial conditions required for the catalytic oxidation of methane in exhaust gas. The high-temperature catalyst promotes deep methane oxidation in subsequent reaction zones and maintains reaction stability. The combination of the inert heat storage body, low-temperature catalyst, and high-temperature catalyst creates a reaction path in the reactor: inlet thermal buffer, low-temperature catalytic start-up, high-temperature catalytic deep oxidation, and outlet thermal buffer. The reactor can adopt various configurations such as particle-packed bed, bed with elevator, fluidized bed, and integral honeycomb. The reactions all occur within confined spaces such as particle gaps, bed pores, or honeycomb channels, restricting the propagation of free flame. Temperature detection point (T0) in the catalytic oxidation reaction zone. ox The reactor outlet high-temperature oxidizing gas temperature detection point (temperature T2) and pressure detection point enable full-process status monitoring.

[0013] The waste heat utilization system includes a waste heat boiler and a user. The high-temperature oxidizing gas from the reactor outlet first enters the waste heat boiler to recover high-grade heat for heating, and then enters the regenerator to preheat the inlet gas, forming a cascade heat utilization. The exhaust gas is finally discharged through the vent.

[0014] The monitoring and control system uses temperature T1 and temperature T ox Temperature T2 is the core control parameter, which, combined with pressure and flow monitoring signals, coordinates the control of energy output, inlet air flow, and valve status to achieve normal operation regulation, early warning classification, and interlock protection. Temperature T1 reflects the reactor inlet preheating conditions, and temperature T... ox Temperature T1 is used to reflect the catalytic oxidation state inside the reactor, while temperature T2 reflects the state of the high-temperature oxidizing gas at the reactor outlet. By analyzing temperatures T1 and T2... ox The coordinated monitoring of temperature T2 enables temperature constraint throughout the entire process from the inlet and reaction zone to the outlet, keeping the reactor in a low-temperature, flameless catalytic oxidation state.

[0015] Furthermore, the reactor is any one of the following: a particle packed bed reactor (PPBR), a particle packed bed reactor (PMBR) with a particle elevator, a particle fluidized bed reactor (PFBR), or an integral honeycomb reactor (MCR), or a combination of the above configurations depending on the processing scale and operational requirements. All four configurations can be equipped with an inert heat storage body, a low-temperature catalyst, and a high-temperature catalyst. The inert heat storage body achieves thermal buffering and flow equalization; the low-temperature catalyst reduces ignition conditions; the high-temperature catalyst enhances deep oxidation capacity; and the confined spaces such as particle gaps, bed pores, or honeycomb channels limit the formation and propagation of free flames, as detailed below: Furthermore, in the granular packed bed reactor (PPBR), an inert heat storage medium, a low-temperature catalyst, a high-temperature catalyst, and another inert heat storage medium are arranged sequentially along the gas flow direction. The inert heat storage medium on the inlet side is used to equalize the flow and thermally buffer the exhaust gas entering the bed. The low-temperature catalyst is used to initiate low-temperature catalytic oxidation, the high-temperature catalyst is used to complete the subsequent deep oxidation, and the inert heat storage medium on the outlet side is used to absorb the heat of the gas after the reaction and smooth out the outlet temperature fluctuations.

[0016] Furthermore, the PMBR (Particle Packed Bed Reactor) with particle elevator is equipped with a particle elevator, and the reactor interior is filled or arranged with inert heat storage medium, low-temperature catalyst, and high-temperature catalyst. The particle elevator is used to lift, circulate, or redistribute particles to improve the heat and mass transfer state of the bed during long-term operation and mitigate the impact of local hot spots, local blockages, or local catalyst failure on system stability.

[0017] Furthermore, the granular fluidized bed reactor (PFBR) incorporates an inert heat storage medium, a low-temperature catalyst, and a high-temperature catalyst, ensuring that the particles are in a fluidized or quasi-fluidized state as the gas passes through the bed. This structure enhances gas-solid contact, improves bed heat and mass transfer efficiency, and reduces local temperature gradients through particle movement, thereby enhancing the stability of the low-concentration exhaust gas catalytic oxidation process.

[0018] Furthermore, the integral honeycomb reactor (MCR) adopts an integral honeycomb channel structure, with an inert heat storage body, a low-temperature catalyst, a high-temperature catalyst, and an inert heat storage body arranged sequentially along the gas flow direction. Exhaust gas flows within the honeycomb channel and contacts the catalyst surface. The honeycomb channel features regular flow channels, low pressure drop, large specific surface area, and significant confined space, which helps improve the uniformity of airflow distribution and limit the propagation space of free flames.

[0019] This invention also provides a control method based on the above system, comprising the following steps: S1. Start-up and Energy Supplementation Preparation: Start the solar thermal module, photovoltaic module, wind power module, and thermal / electrical storage module. Check the thermal and electrical energy reserves of the thermal / electrical storage module to confirm that it can provide the energy required for startup to the gas intake fan, electric regulating valve, shut-off valve, bypass valve, regenerator, and reactor. During the startup phase, keep the shut-off valve closed and the bypass valve open to prevent exhaust gas from entering the reaction zone before the reactor has the necessary oxidation conditions.

[0020] S2. Gas Intake, Pressure Stabilization, and Metering: Start the gas intake fan to allow exhaust gas to enter the main intake pipeline through the exhaust gas inlet, passing sequentially through the pressure stabilizing device, pressure gauge, flow meter, and electric regulating valve. The control system adjusts the operating status of the gas intake fan and the opening of the electric regulating valve based on feedback signals from the pressure gauge and flow meter, ensuring that the pressure and flow rate of exhaust gas entering subsequent units remain stable.

[0021] S3, Intake Access Judgment: The control system determines intake access based on temperature T1 and temperature T... ox The status of temperature T2 and the reactor pressure monitoring points (both the outlet and outlet pressure monitoring points) determines whether the reactor meets the conditions for gas inlet. If temperature T1 is insufficient, temperature T... ox If there is an abnormality, such as an abnormal temperature T2, an abnormal reactor pressure, or an abnormal outlet pressure, close the shut-off valve and open the bypass valve to allow the exhaust gas to be discharged through the vent. If the air intake conditions are met, open the shut-off valve and close the bypass valve to allow the exhaust gas to enter the regenerator.

[0022] S4. Regenerative Preheating Control: After the exhaust gas enters the regenerator, it is preheated by the waste heat passage, forming a temperature T1 between the regenerator outlet and the reactor inlet. The control system adjusts the energy output of the heat storage / electricity storage module and the opening of the electric regulating valve according to the temperature T1, so that the exhaust gas entering the reactor reaches the preheated state required for low-temperature catalytic oxidation, i.e., the preset catalytic ignition range.

[0023] S5. Low-Temperature Catalytic Oxidation Control: Preheated exhaust gas enters the reactor, where low-temperature, flameless catalytic oxidation occurs under the action of an inert heat storage medium, a low-temperature catalyst, and a high-temperature catalyst. The control system collects the temperature T in real time. ox The oxidation state inside the reactor is determined by considering temperature T2 and the pressure monitoring points at both the reactor pressure and outlet. If temperature T... ox If the temperature is too low, increase the supplemental energy or decrease the intake volume; if the temperature T ox If the temperature T2 is too high, reduce the supplementary energy, reduce the intake air volume, or increase the heat extraction intensity of the waste heat boiler.

[0024] S6. Waste heat utilization in stages: The high-temperature oxidizing gas at the reactor outlet enters the waste heat boiler, which recovers heat and supplies heat to users; the gas after heat exchange in the waste heat boiler continues to enter the regenerator, transferring the remaining heat to the inlet exhaust gas; the exhaust gas after heat exchange is discharged through the vent; the control system judges the heat exchange status of the waste heat boiler and the regenerator through various temperature detection points.

[0025] S7. Abnormal Interlock Protection: When the temperature, pressure, flow rate, or energy replenishment status exceeds the safety threshold, the interlock action is executed: cut off the reactor energy replenishment, reduce the electric regulating valve, close the shut-off valve, open the bypass valve, and block the backflow of high-temperature gas and pressure wave through the check valve. The interlock action is executed in stages.

[0026] Level 1 interlock: Temperature T ox When temperature T2 approaches the upper or lower limit of its respective preset range, only the supplementary power and intake flow are adjusted, without switching the valves; Secondary interlock: temperature T1, temperature T... oxWhen any parameter of temperature T2 exceeds the safety threshold, the shut-off valve is closed and the bypass valve is opened, while the regeneration and waste heat system is kept running; three-level interlock: if there is a loss of control of energy replenishment, valve failure or pressure surge, the energy replenishment and air intake are completely cut off, and the system enters the venting and cooling state.

[0027] Furthermore, the preset temperature range for T1 is 260~330℃, and the temperature T... ox The preset temperature range is 320~480℃, and the preset temperature range for T2 is 380~520℃; when temperature T ox When the temperature remains above 550℃, it is considered an overheating risk, triggering a level 2 interlock. When the reactor pressure experiences a negative sudden change or the inlet side pressure rises abnormally, it is considered a backfire / pressure backflow risk, triggering a level 3 interlock.

[0028] Furthermore, the shutdown procedure also includes: first, gradually reduce the supplementary power output and intake air flow, then close the shut-off valve and open the bypass valve, waiting until temperatures T1 and T2 are reached. ox Once the temperature T2 drops below 200℃ and the pressure stabilizes, the air intake fan and the energy replenishment system are stopped, and the system enters standby mode.

[0029] Compared with the prior art, the present invention has the following advantages: 1. This invention couples three types of renewable energy: solar thermal, photovoltaic, and wind power. Through thermal / electrical storage modules, it achieves dual-path buffering and allocation of thermal and electrical energy, enabling stable energy replenishment under operating conditions such as start-up, low concentration, and concentration fluctuations, reducing dependence on fossil fuels and improving the system's continuous operation capability.

[0030] 2. This invention constructs a two-stage waste heat recovery path of "high-grade heating from waste heat boiler - preheating of exhaust gas from regenerator". The heat released by the reaction first meets the user's heating needs and is then used for preheating of the inlet gas, maximizing energy utilization efficiency and reducing external energy consumption.

[0031] 3. This invention uses the temperature T1 and temperature T at different locations in the reactor. ox A temperature monitoring system is constructed with temperature T2 as the core to monitor the temperature throughout the entire process from inlet to reaction zone to outlet. This system is linked to the adjustment of multiple parameters such as energy replenishment, flow rate, and heat extraction. This not only avoids reaction instability caused by insufficient energy replenishment, but also prevents local overheating caused by excessive energy replenishment.

[0032] 4. This invention systematically reduces the risks of thermal runaway, backfire, and pressure backflow through five layers of protection: controllable energy input, cascaded regenerative constraints, full-process temperature monitoring, confined space reaction, and one-way isolation + main circuit cutoff + bypass vent valve group interlocking. This achieves inherent safety through flameless, low-temperature oxidation. Specifically: First, controllable energy input is achieved through an energy storage system, avoiding sudden temperature rises in the reactor caused by single high-intensity external heating. Second, cascaded heat utilization is achieved through a regenerator and waste heat boiler, allowing the system to maintain reactor inlet preheating while reducing external energy input. Third, temperature T1 and temperature T... ox The temperature T2 enables full-process temperature monitoring of the inlet, reaction zone, and outlet. Fourth, the free flame propagation space is restricted through confined space reaction structures such as PPBR, PMBR, PFBR, or MCR. Fifth, flow isolation and bypass venting under abnormal operating conditions are achieved through check valves, shut-off valves, bypass valves, and vent ports.

[0033] 5. The reactor of this invention supports a variety of conventional catalytic oxidation configurations, and can be flexibly selected according to the processing scale and concentration conditions; the system can be used for the harmless destruction of exhaust gas, and can also simultaneously provide heating and power to the mining area, adapting to the actual needs of different coal mines. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the overall process of the present invention.

[0035] Figure 2 This is a schematic diagram of four optional configurations of the reactor in this invention.

[0036] In the diagram: 1-Photothermal module; 2-Photovoltaic module; 3-Wind power module; 4-Heat storage / Electricity storage module; 5-User; 6-Gas intake fan; 7-Pressure stabilizer; 8-Pressure gauge; 9-Flow meter; 10-Electric regulating valve; 11-Check valve; 12-Shut-off valve; 13-Bypass valve; 14-Regenerator; 15-Waste heat boiler; 16-Reactor; 17-Temperature detection point; 18-Reactor inlet preheating temperature detection point (T1); 19-Reactor outlet high-temperature oxidizing gas temperature detection point (T2); 20-Temperature detection point; 21-Exhaust side temperature detection point; 22-Catalytic oxidation reaction zone temperature detection point (Tox); 23-Reactor pressure detection point; 24-Outlet pressure detection point; 25-Exhaust port; 26-Exhaust gas inlet. Detailed Implementation

[0037] The present invention will be further described below.

[0038] Example 1: This example handles an air volume of 10,000 m³ / h. 3A coal mine exhaust gas treatment system with a capacity of / h can treat methane volume concentrations of 0.2% to 0.8%, with a gas source pressure fluctuation range of ±200Pa. The system is designed to have a methane oxidation efficiency of ≥95% and can also provide domestic hot water and wellhead antifreeze heating to the mining area.

[0039] 1. System Configuration (1) Energy storage system: Solar thermal module 1 adopts a parabolic trough solar collector array with a collection area of ​​200m². 2 The rated heat collection power is 120kW, and the output heat transfer oil temperature is 350℃; the photovoltaic module 2 adopts a monocrystalline silicon photovoltaic array with an installed capacity of 100kWp; the wind power module 3 adopts two 50kW small horizontal axis wind turbines; the thermal / electrical storage module 4 includes a phase change thermal storage unit and a lithium iron phosphate electrical storage unit: the phase change thermal storage unit adopts nitrate phase change material, the phase change temperature is 350℃, and the thermal storage capacity is 500kWh; the electrical storage unit has a capacity of 200kWh and has a voltage stabilization output function.

[0040] The thermal / electricity storage module 4 outputs three paths: ① System energy replenishment output: maximum heating power 150kW, connected to the heat replenishment coils of the regenerator 14 and reactor 16; ② System power consumption output: rated voltage 380V, supplying power to the air intake fan 6, valve actuator and monitoring and control system; ③ User energy supply output: heating / power supply can be switched, and surplus energy is output to user 5.

[0041] (2) Exhaust gas supply system: The intake fan 6 adopts a centrifugal fan with a rated air volume of 12000 m³ / h. 3 / h, total pressure 1500Pa; pressure stabilizing device 7 adopts a volumetric pressure stabilizing tank with an effective volume of 5m³, reducing gas source pressure fluctuations; pressure gauge 8 has a range of 0~2000Pa and an accuracy of 0.5 grade; flow meter 9 adopts a thermal gas mass flow meter with a range of 0~15000m³. 3 / h; The electric regulating valve 10 adopts an electric ventilation butterfly valve with an adjustment accuracy of ±1% and a response time of ≤2s.

[0042] (3) Valve group safety switching system: One-way valve 11 adopts a micro pressure check valve with an opening pressure ≤50Pa and a reverse sealing pressure ≥5000Pa; shut-off valve 12 adopts a pneumatic quick shut-off butterfly valve with a closing time ≤1s; bypass valve 13 adopts an electric butterfly valve, which is interlocked and mutually exclusive with shut-off valve 12; the exhaust port 25 is equipped with a rainproof wind cap with an exhaust height of 15m.

[0043] (4) Regenerative preheating system: Regenerator 14 adopts a shell-and-tube gas-to-gas heat exchanger with a heat exchange area of ​​180m². 2 The design heat exchange efficiency is ≥70%, and the high-temperature side inlet temperature is ≤550℃.

[0044] (5) Intrinsically safe oxidation reaction system: Reactor 16 adopts a particle packed bed reactor (PPBR), a vertical cylindrical structure with an inner diameter of 1.8m and a total bed height of 1.5m. The bed is filled sequentially along the airflow direction as follows: ① Inlet side inert heat storage body: φ20mm alumina ceramic balls, filling thickness 300mm, porosity 42%; ② Low temperature catalyst: Pd-based honeycomb ceramic catalyst, with cordierite as the support, Pd loading 0.3%, ignition temperature 250℃, filling thickness 400mm; ③ High temperature catalyst: Pt-Pd composite honeycomb ceramic catalyst, Pt-Pd total loading 0.5%, optimal activity temperature 350~500℃, filling thickness 500mm; ④ Outlet side inert heat storage body: φ20mm alumina ceramic balls, filling thickness 300mm. The reactor shell is equipped with a heat insulation layer with a thickness of 150mm.

[0045] Temperature monitoring point layout: Preheating temperature monitoring point 18 at the reactor inlet is located in the reactor inlet pipeline; temperature monitoring point 22 in the catalytic oxidation reaction zone is arranged in the middle of the bed, with a total of 3 points evenly distributed along the cross-section, and the average value is taken as the control value; high-temperature oxidizing gas temperature monitoring point 19 at the reactor outlet is located in the reactor outlet pipeline. Pressure monitoring point 23 is arranged in the upper part of the bed.

[0046] (6) Waste heat utilization system: Waste heat boiler 15 adopts shell and tube type waste heat steam / hot water boiler with rated heat production power of 180kW and outlet water temperature of 85℃, and is connected to the mining area heating network; User 5 is the mining area domestic hot water and wellhead antifreeze system.

[0047] (7) Monitoring and control system: The system adopts a PLC control system, equipped with a touch screen and remote communication module, to collect all temperature, pressure, flow and valve status signals, and has built-in hierarchical control and interlock protection logic, with a control cycle of ≤500ms.

[0048] 2. Operation control methods and parameters S1, Startup Phase: ① Start the solar thermal module 1, photovoltaic module 2, wind power module 3 and thermal / electricity storage module 4, and confirm that the temperature of the thermal storage unit is ≥320℃ and the SOC of the electricity storage unit is ≥50%; keep the shut-off valve 12 closed and open the bypass valve 13.

[0049] ② Start the intake fan 6 and adjust the electric regulating valve 10 to stabilize the intake flow rate at 5000 m³ / h. 3 / h, exhaust gas is discharged directly through bypass valve 13 and vent 25.

[0050] ③ The thermal / electrical storage module 4 outputs heating power to the heating coil of reactor 16, raising the temperature at a rate of 5℃ / min; when the temperature T ox When the temperature rises to 300℃ and temperature T1 rises to 260℃, the intake conditions are deemed met.

[0051] S2, Stable Operation Phase ① Open the shut-off valve 12 and close the bypass valve 13. The exhaust gas enters the regenerator 14 for preheating and then enters the reactor 16; gradually increase the intake flow rate to the rated 10,000 m³ / h. 3 / h.

[0052] ② Temperature control target: Maintain temperature T1 at 280~320℃, temperature T ox Maintain at 350~450℃, and maintain temperature T2 at 400~500℃.

[0053] ③ Control Logic: When temperature T1 < 280℃ and temperature T ox When the temperature is below 350℃, increase the energy replenishment power of the thermal storage module or reduce the air intake flow rate by 10%~20%.

[0054] When temperature T ox When the temperature is >450℃ or the temperature T2 is >500℃, reduce the supplementary power to 0, while increasing the water circulation flow rate of the waste heat boiler to enhance heat extraction, and reduce the air intake flow rate if necessary.

[0055] Under normal operating conditions, more than 80% of the heat released by the reaction is recovered by the waste heat boiler, and the remaining waste heat is recovered by the regenerator. The system's supplementary power is maintained at 10% to 30% of the rated power, mainly playing a regulatory role.

[0056] S3, Abnormal Interlock Protection ① Level 1 Interlock: Temperature T ox If the temperature is ≥480℃ or ≤320℃ and remains at that temperature for 30 seconds, the system will automatically adjust the energy replenishment and air intake flow, issue an audible and visual warning, and will not switch valves.

[0057] ② Secondary interlock: Temperature T ox If the temperature reaches ≥550℃ or T2 ≥580℃, or the reactor pressure suddenly rises to ≥1000Pa / s, the protection interlock is triggered: immediately close the shut-off valve 12, open the bypass valve 13, cut off the reactor's energy output, reduce the opening of the electric regulating valve 10 to 20%, and automatically block the reverse airflow with the one-way valve 11.

[0058] ③ Three-level interlock: In case of valve failure, loss of power supply control, or temperature T ox Emergency shutdown at ≥600℃: Completely close the electric regulating valve 10, stop the air intake fan 6, cut off all supplementary power output, and allow the system to cool down naturally.

[0059] S4, Shutdown Phase ① Gradually reduce the supplementary power to 0, and simultaneously reduce the intake airflow to 3000m³. 3 / h, maintain for 30min.

[0060] ② Close the shut-off valve 12 and open the bypass valve 13 to continue ventilation and cooling.

[0061] ③ Waiting for temperature T1, temperature T ox Once the temperature T2 drops below 200℃ and the reactor pressure stabilizes, the gas extraction fan 6 and the energy storage system are stopped, and the system enters standby mode.

[0062] 3. Implementation Results: This embodiment can operate continuously and stably under methane concentration fluctuations of 0.3%~0.7%, with methane oxidation efficiency consistently above 96%; the overall energy utilization rate of the system is improved by about 25% compared to a single catalytic oxidation system, and renewable energy accounts for more than 60% of the supplementary energy; under abnormal operating conditions, the valve interlock response time is ≤1s, and no backfire or thermal runaway occurs, and the safety performance meets the inherent safety requirements for underground gas source treatment in coal mines.

[0063] Example 2: The difference between this example and Example 1 is that reactor 16 adopts an integral honeycomb reactor (MCR), with a cordierite honeycomb carrier pore density of 200 mesh. The channels are sequentially coated with an inert heat storage coating, a low-temperature catalyst coating, and a high-temperature catalyst coating. The channel dimensions are uniform, and the pressure drop is lower than that of a packed bed reactor, making it suitable for low-pressure head exhaust gas sources. The remaining system configuration and control methods are the same as in Example 1, achieving stable low-temperature catalytic oxidation and safety interlock protection.

[0064] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An intrinsically safe exhaust gas supplementation oxidation system, characterized in that, This includes a supplementary energy storage system, a waste gas supply system, a valve group safety switching system, a regenerative preheating system, an intrinsically safe oxidation reaction system, a waste heat utilization system, and a monitoring and control system. The exhaust gas supply system, the regenerative preheating system, the intrinsically safe oxidation reaction system, and the waste heat utilization system are connected sequentially along the gas flow direction, wherein the waste heat utilization system and the regenerative preheating system form a heat exchange loop. The energy storage system includes a solar thermal module, a photovoltaic module, a wind power module, and a thermal / electrical storage module. The solar thermal module, photovoltaic module, and wind power module are respectively connected to the thermal / electrical storage module. The thermal / electrical storage module is equipped with three outputs: an output to supply energy to the regenerative preheating system and the intrinsically safe oxidation reaction system, an output to supply power to the system's electrical equipment, and an output to supply energy to the user. The valve group safety switching system includes a one-way valve and a shut-off valve arranged sequentially in the intake main pipeline, and a bypass valve connected in parallel between the front end of the shut-off valve and the vent, forming a safety switching structure with one-way backflow prevention and switching between the shut-off valve and the bypass valve. The intrinsically safe oxidation reaction system includes a confined space reactor filled with an inert heat storage body, a low-temperature catalyst and a high-temperature catalyst. The reactor is equipped with a reactor inlet preheating temperature detection point, a catalytic oxidation reaction zone temperature detection point and a reactor outlet high-temperature oxidizing gas temperature detection point. The monitoring and control system is connected to the energy replenishment and storage system, the exhaust gas supply system, and the valve group safety switching system, respectively. It is used to coordinate and adjust the energy replenishment output of the thermal / electrical storage module, the air intake flow of the exhaust gas supply system, and the opening and closing status of the shut-off valve and the bypass valve based on the real-time monitoring values ​​of each temperature detection point in the reactor.

2. The system according to claim 1, characterized in that, The exhaust gas supply system includes an exhaust gas inlet, a gas intake fan, a pressure stabilizing device, a pressure gauge, a flow meter, and an electric regulating valve arranged sequentially along the airflow direction. The electric regulating valve is connected to the monitoring and control system, and the adjustment is based on at least the pressure signal from the pressure gauge, the flow signal from the flow meter, and the real-time monitoring values ​​of each temperature detection point in the reactor.

3. The system according to claim 1, characterized in that, The regenerative preheating system includes a regenerator; the waste heat utilization system includes a waste heat boiler and users; the high-temperature oxidizing gas at the reactor outlet first extracts heat from the waste heat boiler to supply energy to users, and then exchanges heat with the exhaust gas through the regenerator before being discharged through the vent, forming a cascade heat utilization path of high-grade heat extraction from the waste heat boiler and preheating of exhaust gas by the regenerator.

4. The system according to claim 1, characterized in that, The reactor is any one of the following: granular packed bed reactor (PPBR), granular packed bed reactor (PMBR) with granular elevator, granular fluidized bed reactor (PFBR), or monolithic honeycomb reactor (MCR).

5. The system according to claim 1, characterized in that, The thermal / electric storage module includes a phase change thermal storage unit and an electrochemical electric storage unit. During the start-up phase, it prioritizes outputting supplementary thermal energy to the regenerator and reactor. During the stable operation phase, it mainly relies on waste heat recovery and supplementary energy regulation. Under low concentration fluctuation conditions, it dynamically corrects the supplementary energy power based on the real-time monitoring values ​​of each temperature detection point in the reactor.

6. The system according to claim 1, characterized in that, The monitoring and control system is also connected to the reactor pressure detection point and the outlet pressure detection point. When the temperature of the reactor inlet preheating temperature detection point is lower than the inlet air threshold, the temperature of the catalytic oxidation reaction zone temperature detection point is too high, the reactor pressure is abnormal or there is a pressure backflow trend, the interlock action is executed: cut off the reactor side energy supplement output, reduce the inlet air flow, close the shut-off valve, and open the bypass valve.

7. An intrinsically safe method for supplementing exhaust gas with oxidation, implemented based on the system described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Start-up and energy replenishment preparation: Start the solar thermal module, photovoltaic module, wind power module and thermal / electric energy storage module, and confirm that the energy reserves meet the start-up requirements; during the start-up phase, keep the shut-off valve closed and the bypass valve open. S2. Gas intake pressure stabilization and metering: Start the gas intake fan. After the exhaust gas is stabilized by the pressure stabilization device, it is monitored in real time by the pressure gauge and flow meter. The intake flow and pressure are adjusted to the set range by the electric regulating valve. S3. Inlet Gas Access Judgment: Determine the inlet gas conditions based on the temperature at each temperature detection point and the reactor pressure; if the conditions are not met, keep the shut-off valve closed and the bypass valve open, and directly vent the exhaust gas; if the conditions are met, open the shut-off valve and close the bypass valve. S4. Regenerative Preheating Control: Exhaust gas enters the regenerator and exchanges heat with the waste heat of the tail gas for preheating. The monitoring and control system adjusts the energy replenishment power and air intake flow of the heat storage / electricity storage module according to the temperature T1 at the reactor inlet preheating temperature detection point, so that the temperature T1 is maintained within the preset range of catalytic ignition. S5. Low-Temperature Catalytic Oxidation Control: Preheated exhaust gas enters the reactor, where flameless catalytic oxidation occurs under the buffering effect of an inert heat storage body and the staged action of low-temperature and high-temperature catalysts; the temperature T at the temperature detection point in the catalytic oxidation reaction zone is collected in real time. ox The temperature T2 at the high-temperature oxidizing gas temperature detection point at the reactor outlet and the reactor pressure are monitored. If the temperature is lower than the preset range, the supplementary energy is increased or the gas intake is reduced. If the temperature is higher than the preset range, the supplementary energy is reduced, the waste heat extraction intensity is increased, or the gas intake is reduced. S6. Waste heat utilization in stages: The high-temperature oxidizing gas at the reactor outlet first enters the waste heat boiler to recover high-grade heat to supply heat to users, and then enters the regenerator to preheat the exhaust gas. After heat exchange, the exhaust gas is discharged through the vent. S7. Abnormal Interlock Protection: When the temperature, pressure, flow rate, or energy replenishment status exceeds the safety threshold, the interlock action is executed: cut off the reactor energy replenishment, reduce the electric regulating valve, close the shut-off valve, open the bypass valve, and block the backflow of high-temperature gas and pressure wave through the check valve.

8. The method according to claim 7, characterized in that, The preset temperature range for T1 is 260~330℃. ox The preset temperature range is 320~480℃, and the preset temperature range for T2 is 380~520℃; when temperature T ox If the temperature remains above 550℃, it is considered an overheating risk, triggering a level two interlock. When the reactor pressure experiences a negative sudden change or the inlet side pressure rises abnormally, it is determined to be a risk of backfire / pressure backflow, triggering a three-level interlock.

9. The method according to claim 8, characterized in that, The interlocking action in step S7 is executed in stages: Level 1 interlock: Temperature T ox When the temperature T2 approaches the upper or lower limit of its respective preset range, only the supplementary power and intake flow are adjusted, without switching the valves; Two-level interlock: Temperature T1, Temperature T ox When any parameter of temperature T2 exceeds the safety threshold, close the shut-off valve and open the bypass valve, while keeping the regeneration and waste heat system running. Three-level interlock: If there is a loss of control over energy supply, valve failure, or sudden pressure rise, the energy supply and air intake will be completely cut off, and the system will enter the venting and cooling state.

10. The method according to claim 7, characterized in that, It also includes shutdown procedures: first, gradually reduce the supplementary power output and intake air flow, then close the shut-off valve and open the bypass valve, waiting for temperatures T1 and T2 to reach a certain value. ox Once the temperature T2 drops below 200℃ and the pressure stabilizes, the air intake fan and the energy replenishment system are stopped, and the system enters standby mode.

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