Automatic switching type mixed gas drying and dewatering system based on flue gas waste heat

Abstract

The utility model discloses an automatic switching type mixed gas drying and dewatering system based on flue gas waste heat. At present, gas emission harm is large, an existing gas utilization device has requirements for gas concentration and needs drying and dewatering, and a traditional refrigerator drying technology is high in energy consumption and high in cost. The system comprises a gas conveying and shunting device, a dehydration device, a humidity monitoring and control device, a waste heat utilization device, a water vapor discharge device and the like. Gas is conveyed and shunted through the gas conveying and shunting device; a dehydration unit of the dehydration device is provided with a water absorption and heat exchange assembly; the humidity monitoring and control device automatically switches branches according to humidity monitoring results; the waste heat utilization device uses flue gas waste heat to dry the water absorption assembly; and the water vapor discharging device discharges redundant water vapor. The water absorption assembly is made of a vermiculite porous material with good air permeability, and the heat exchange tube is spiral. The system utilizes flue gas waste heat, realizes automatic switching and efficient dehydration, reduces energy consumption and cost, and improves economical efficiency and stability of gas utilization and equipment reliability.

Description

Technical Field

[0001] This utility model belongs to the field of low-concentration coal mine gas utilization, specifically involving an automatic switching mixed gas drying and dehydration system based on flue gas waste heat and related technologies. Background Technology

[0002] Methane (CH4) is the main component of coal mine gas. The methane concentration in extracted coal mine gas typically exceeds 5%, while existing gas utilization equipment generally requires a methane concentration below 1.2% in the raw gas for effective utilization. Therefore, extracted coal mine gas needs to be mixed with other gases to reduce the methane concentration. However, extracted coal mine gas often contains a large amount of water vapor, resulting in high humidity. The water vapor in high-humidity coal mine gas can affect subsequent gas utilization, such as affecting gas stability, causing equipment corrosion, and reducing equipment operating efficiency. Therefore, drying and dehydration treatment is a necessary step in coal mine gas utilization.

[0003] Currently, coal mine gas drying and dehydration mainly employs refrigeration drying technology. While this technology achieves the drying objective, it has significant limitations. Refrigeration drying requires additional energy support, increasing energy consumption and resulting in high operating and maintenance costs. As the scale of coal mine gas utilization continues to expand, rising energy costs and equipment maintenance expenses lead to a decline in the economic viability of gas utilization. Therefore, developing a drying and dehydration method and system that can efficiently remove water vapor while achieving low-cost operation without increasing additional energy input has become a pressing technical challenge for the industry. Utility Model Content

[0004] In view of the shortcomings of the prior art, the purpose of this utility model is to provide an automatic switching type mixed gas drying and dehydration system based on flue gas waste heat, which solves the problem of high humidity gas being difficult to dry and dehydrate at low cost, overcomes the defects of high energy consumption and high cost of existing refrigeration drying technology, meets the gas drying needs of coal mine gas utilization, and at the same time improves the economy and stability of gas utilization and reduces equipment corrosion.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] This utility model discloses an automatic switching type mixed gas drying and dehydration system based on flue gas waste heat, comprising: a gas conveying and diverting device configured to convey the mixed gas through a conveying pipeline and divert it into two branches; a dehydration device comprising at least two dehydration units, each dehydration unit being equipped with a water absorption component for removing water vapor from the gas and a heat exchange component for drying the gas when the water absorption component is saturated, each dehydration unit being connected to one of the two branches; and a humidity monitoring and control device, wherein a humidity monitoring and control device is installed at the outlet of each dehydration unit. The system includes a humidity monitoring component to monitor the humidity of the gas in real time and control the opening and closing of the branch based on the monitoring results. When the humidity of the gas at the outlet of a dehydration unit exceeds a preset threshold, the branch where the dehydration unit is located is closed, while another branch is opened. The waste heat utilization device connects the heat exchange component of the water-saturated dehydration unit to the flue gas outlet of the gas utilization device when the dehydration unit is switched, so as to use the waste heat of the flue gas to dry the water absorption component. The water vapor emission device is connected to the dehydration unit and is used to discharge the excess water vapor generated during the drying process into the external atmosphere.

[0007] In this invention, the system utilizes the waste heat from the flue gas generated by the gas utilization device to dry the water absorption component, eliminating the need for additional energy and avoiding the high energy consumption and high cost problems of traditional refrigeration drying technology. This not only reduces the energy consumption and operating costs of gas drying and dehydration but also realizes the recovery and utilization of waste heat from the waste flue gas, improving the overall energy utilization efficiency of the system and enabling more efficient use of resources.

[0008] Furthermore, the humidity monitoring and control device monitors the gas humidity in real time and automatically switches the dehydration unit, ensuring the continuous and stable drying and dehydration process, improving dehydration efficiency, and reducing equipment downtime. Simultaneously, the efficient removal of water vapor from the gas reduces gas humidity, minimizing corrosion of the equipment and providing a higher-quality gas source for subsequent gas utilization, thus enhancing the stability of gas utilization. In addition, the water vapor emission device prevents water accumulation inside the system, and the dehydration unit's outer shell uses insulation material to improve waste heat utilization efficiency, enhancing the system's integrity and reliability and ensuring stable operation.

[0009] This invention relates only to improvements in hardware devices and their interconnections, and does not involve any improvements to algorithms or programs. Any calculations involved can be implemented using existing technology, and will not be elaborated upon here.

[0010] According to the automatic switching mixed gas drying and dehydration system based on flue gas waste heat disclosed in this utility model, the water absorption component in the dehydration device is a porous material, and the porous material is vermiculite with a porous structure.

[0011] In this invention, vermiculite's unique layered porous structure provides abundant internal pores and a large specific surface area, significantly increasing the contact area with water vapor in methane gas. This allows for efficient moisture adsorption, and its excellent permeability ensures smooth gas flow and rapid water vapor diffusion and adsorption, significantly improving dehydration efficiency and rapidly reducing methane gas humidity to meet subsequent utilization requirements. Furthermore, when utilizing waste heat from flue gas for drying, its good permeability facilitates rapid water vapor escape, allowing vermiculite to quickly regain its water absorption capacity. This enables frequent recycling of the dehydration unit, and the stable structure of vermiculite maintains good adsorption performance even after multiple cycles, reducing maintenance and replacement costs. In addition, vermiculite is chemically stable, does not react with methane gas, and does not pollute the gas, meeting the requirements for subsequent methane utilization. It also ensures smooth gas flow during system operation, enhancing the reliability and stability of the entire drying and dehydration system.

[0012] According to the automatic switching type mixed gas drying and dehydration system based on flue gas waste heat disclosed in this utility model, the heat exchange component includes multiple heat exchange tubes arranged in parallel. The tube walls of the heat exchange tubes are thermally conductive, and their internal channels are used for flue gas circulation.

[0013] In this invention, the multiple parallel tubes increase the contact area with the flue gas and the water absorption assembly, allowing for more thorough heat transfer. The highly thermally conductive tube walls quickly conduct heat from the flue gas to the water absorption assembly, improving drying efficiency. Internal channels facilitate flue gas circulation, fully utilizing waste heat for efficient energy use. Simultaneously, the flue gas ensures a stable supply of heat to the water absorption assembly, guaranteeing efficient recovery of the water absorption capacity after the absorption assembly becomes saturated. This enhances the overall operational efficiency and stability of the gas drying and dehydration system.

[0014] According to the automatic switching mixed gas drying and dehydration system based on flue gas waste heat disclosed in this utility model, the heat exchange tube has a spiral structure to increase the area and time of heat transfer between the heat exchange tube and the flue gas and water absorption components, thereby improving the drying effect.

[0015] In this invention, the heat exchange tubes adopt a spiral structure, which significantly enhances the performance of the gas drying and dehydration system. The spiral design greatly increases the heat transfer area between the heat exchange tubes and the flue gas and water absorption components, allowing for more heat exchange; it also extends the heat transfer time, enabling more efficient utilization of the flue gas's waste heat, thereby effectively improving the drying effect on the water absorption components. This not only ensures that the water absorption components can quickly recover their water absorption capacity, guaranteeing the continuous and stable operation of the dehydration unit, but also further improves the overall system's dehydration efficiency, providing strong support for the efficient drying and dehydration of gas and enhancing the quality of subsequent gas utilization.

[0016] According to the automatic switching mixed gas drying and dehydration system based on flue gas waste heat disclosed in this utility model, the humidity monitoring component in the humidity monitoring and control device is a capacitive humidity sensor.

[0017] In this invention, the capacitive humidity sensor has a fast response speed, enabling it to quickly detect changes in the humidity of the gas and monitor the humidity of the gas at the outlet of each dehydration unit in real time and accurately. This allows the system to promptly detect humidity anomalies caused by water saturation in the dehydration unit, providing accurate data for subsequent control of branch opening and closing. It ensures that when the gas humidity exceeds a preset threshold, the system can react quickly and automatically switch to a backup dehydration unit, ensuring the continuous and stable operation of the gas drying and dehydration process. This effectively avoids poor dehydration results due to untimely humidity monitoring, improving the reliability and operating efficiency of the entire drying and dehydration system.

[0018] According to the automatic switching mixed gas drying and dehydration system based on flue gas waste heat disclosed in this utility model, the actuator for controlling the opening and closing state of the branch in the humidity monitoring and control device is an electric valve.

[0019] In this invention, the electric valve responds rapidly. When the humidity monitoring component detects that the humidity of the gas at the outlet of a dehydration unit exceeds a preset threshold, it quickly receives a control signal and precisely executes the operation of closing the branch containing that dehydration unit and opening another branch. This enables rapid switching of dehydration units, ensuring the continuity of the gas drying and dehydration process and preventing the dehydration effect from being affected by untimely switching. Simultaneously, the electric valve can be automatically controlled and works in conjunction with the humidity monitoring component without manual intervention, improving the system's automation level, reducing labor costs, and ensuring accurate and reliable operation. This effectively reduces the probability of malfunctions and guarantees the stable and efficient operation of the entire system.

[0020] According to the automatic switching mixed gas drying and dehydration system based on flue gas waste heat disclosed in this utility model, a mixed gas temperature sensor is installed on the conveying pipeline in the gas conveying and diversion device to monitor the gas temperature.

[0021] In this invention, by monitoring the gas temperature in real time, operators can promptly grasp the gas status. When abnormal temperature fluctuations occur, they can quickly determine if there are potential system faults, such as local overheating during transport that could pose a safety risk, and then take corresponding measures to ensure the safe operation of the system. Furthermore, the temperature data can provide a reference for subsequent dehydration and waste heat utilization processes. For example, the operating parameters of the dehydration unit or the heat distribution strategy of the waste heat utilization device can be adjusted based on the temperature, enabling the system to be optimized and controlled according to the actual gas temperature, improving overall operating efficiency and ensuring that the gas drying and dehydration work is carried out under optimal conditions.

[0022] According to the automatic switching mixed gas drying and dehydration system based on flue gas waste heat disclosed in this utility model, the water vapor emission device includes an exhaust pipe connected to the dehydration unit, and a one-way valve is provided at the outlet of the exhaust pipe to prevent backflow of outside air.

[0023] In this invention, the exhaust pipe provides a discharge channel for excess water vapor generated during the drying process, preventing its accumulation within the system and thus preventing water corrosion and disruption of normal system operation. The one-way valve at the outlet effectively prevents backflow of outside air into the system, maintaining a stable drying environment inside the dehydration unit. This not only ensures the drying effect of the water absorption component, enabling it to continuously and efficiently adsorb water vapor from the gas, but also prevents humid outside air from mixing with the gas, guaranteeing the dryness of the gas and providing a reliable guarantee for subsequent gas utilization, thereby improving the reliability and stability of the entire drying and dehydration system.

[0024] According to the automatic switching mixed gas drying and dehydration system based on flue gas waste heat disclosed in this utility model, the outer shell of the dehydration unit is made of heat insulation material to reduce heat loss and improve waste heat utilization efficiency.

[0025] In this invention, the insulation material effectively reduces heat loss, ensuring that when the heat exchange component utilizes waste heat from the flue gas to dry the water absorption component, more heat is concentrated inside the dehydration unit, preventing a large amount of heat from being wasted in the surrounding environment. This not only improves waste heat utilization efficiency, allowing for more complete use of flue gas waste heat and reducing energy consumption, but also maintains a higher temperature inside the dehydration unit, accelerating the evaporation rate of moisture in the water absorption component and enabling it to recover its water absorption capacity more quickly. This, in turn, improves the overall efficiency of the dehydration unit and ensures the stable and efficient operation of the gas drying and dehydration system.

[0026] The advantages of this utility model compared to the prior art are as follows:

[0027] 1) Existing refrigeration drying technology relies on additional energy, which is costly. This invention utilizes the waste heat from the flue gas generated by the gas utilization device to dry the water absorption component, eliminating the need for additional energy input, avoiding high energy consumption, greatly reducing energy consumption and operating costs, and improving the economic efficiency of gas utilization.

[0028] 2) This system monitors the humidity of methane gas in real time through a humidity monitoring and control device. A capacitive humidity sensor quickly and accurately detects humidity changes. When the humidity of the methane gas at the outlet of a dehydration unit exceeds a preset threshold, the electric valve actuates rapidly, automatically switching the dehydration unit to ensure a continuous and stable drying process. This not only reduces equipment downtime but also improves dehydration efficiency, better meeting the actual needs of methane drying and dehydration compared to traditional methods.

[0029] 3) This utility model recovers and utilizes the waste heat of flue gas that was originally discarded during the gas utilization process. Through multiple parallel heat exchange tubes with heat-conducting pipe walls and flue gas passing through the inside, especially the spiral structure heat exchange tubes, the heat transfer area and time are increased, and the waste heat drying and water absorption components are fully utilized, thereby improving the overall system's energy utilization efficiency and realizing the comprehensive utilization of resources.

[0030] 4) This system efficiently removes water vapor from methane gas, reducing water vapor corrosion of equipment and improving equipment operating efficiency. Simultaneously, it provides a higher-quality gas source with acceptable humidity for subsequent methane utilization, enhancing the stability and safety of methane utilization.

[0031] 5) A one-way valve is installed at the outlet of the exhaust pipe of the steam emission device to prevent backflow of outside air and avoid the mixing of water and humid air into the gas inside the system; the shell of the dehydration unit is made of heat-insulating material to reduce heat loss and improve waste heat utilization efficiency. These designs comprehensively enhance the integrity and reliability of the system, ensuring long-term stable operation.

[0032] The present invention, an automatic switching mixed gas drying and dehydration system based on flue gas waste heat, is disclosed in detail below with reference to the embodiments shown in the accompanying drawings and the reference numerals. Attached Figure Description

[0033] Figure 1 This is a diagram showing the overall structure and workflow of the automatic switching mixed gas drying and dehydration system based on flue gas waste heat.

[0034] Figure Labels

[0035] 1. Gas conveying and diversion device; 101 Mixed gas temperature sensor; 2. Dehydration device; 201 Dehydration unit; 2011 Heat exchange tube; 2012 Vermiculite; 3. Humidity monitoring and control device; 301 Capacitive humidity sensor; 302 Electric valve; 4. Waste heat utilization device; 401 Flue gas waste heat inlet temperature sensor; 402 Flue gas waste heat outlet temperature sensor; 5. Water vapor emission device; 501 Water vapor emission temperature sensor; 6. Mixed gas inlet; 7. Dry gas outlet; 8. Gas utilization device. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0037] like Figure 1 As shown, this utility model discloses an automatic switching type mixed gas drying and dehydration system based on flue gas waste heat, including a gas conveying and diversion device 1, a dehydration device 2, a humidity monitoring and control device 3, a waste heat utilization device 4, and a water vapor emission device 5. The gas conveying and diversion device 1 is configured to convey the mixed gas through a conveying pipeline and divert it into two branches; the dehydration device 2 includes at least two dehydration units 201, each equipped with a water absorption component for removing water vapor from the gas and a heat exchange component for drying the gas when the water absorption component is saturated. Each dehydration unit 201 is connected to one of the two branches; the humidity monitoring and control device 3 is equipped with a humidity monitoring component at the outlet of each dehydration unit 201 to monitor the humidity of the gas in real time; and Based on the monitoring results, the opening and closing status of the control branch is controlled. When the humidity of the gas at the outlet of a certain dehydration unit 201 exceeds the preset threshold, the branch where the dehydration unit 201 is located is closed, and another branch is opened at the same time. When the dehydration unit 201 is switched, the waste heat utilization device 4 connects the heat exchange component of the water-saturated dehydration unit 201 to the flue gas outlet of the gas utilization device 8 so as to use the waste heat of the flue gas to dry the water absorption component. The water vapor emission device 5 is connected to the dehydration unit 201 and is used to discharge the excess water vapor generated during the drying process to the outside atmosphere.

[0038] In this invention, the system utilizes the waste heat from the flue gas generated by the gas utilization device 8 to dry the water absorption component. This avoids the high energy consumption and high cost problems of traditional refrigeration drying technology, reduces the energy consumption and operating costs of gas drying and dehydration, and realizes the recovery and utilization of waste heat from the flue gas, improving the overall system's energy utilization efficiency and making fuller use of resources. The humidity monitoring and control device 3 monitors the gas humidity in real time and automatically switches the dehydration unit 201 to ensure the continuous and stable drying and dehydration process, improves dehydration efficiency, reduces equipment downtime, and efficiently removes water vapor, reducing gas humidity, reducing corrosion to equipment, providing a better gas source for subsequent gas utilization, and improving the stability of gas utilization. In addition, the water vapor emission device 5 prevents water accumulation inside the system, and the shell of the dehydration unit 201 uses insulation material to improve waste heat utilization efficiency, enhancing the system's integrity and reliability, and ensuring stable system operation.

[0039] like Figure 1As shown, in a preferred embodiment, the water absorption component of the dehydration device 2 uses vermiculite 2012, which has a porous structure and good air permeability. Vermiculite 2012, with its unique layered porous structure, abundant internal pores, and large specific surface area, greatly increases the contact area with water vapor in the gas, thus enabling efficient moisture adsorption. Its good air permeability not only allows the gas to pass through smoothly but also allows water vapor to diffuse and be adsorbed quickly, significantly improving dehydration efficiency and rapidly reducing the humidity of the gas to meet the needs of subsequent gas utilization.

[0040] During the waste heat drying process of flue gas, the excellent air permeability of vermiculite 2012 facilitates the rapid escape of moisture, allowing it to regain its water absorption capacity more quickly and enabling frequent recycling of the dehydration unit 201. Furthermore, vermiculite 2012 is chemically stable, does not react with methane gas, and does not pollute the gas, fully meeting the relevant requirements for subsequent methane utilization.

[0041] like Figure 1 As shown in this embodiment of the invention, the heat exchange assembly consists of multiple heat exchange tubes 2011 arranged in parallel. The tube walls of these heat exchange tubes 2011 have good thermal conductivity, and their internal channels are used for flue gas circulation.

[0042] In this implementation, the parallel arrangement of multiple heat exchange tubes 2011 effectively increases the contact area with the flue gas and the water absorption assembly, allowing for more thorough heat transfer. The tube walls, with their excellent thermal conductivity, quickly conduct heat from the flue gas to the water absorption assembly, thereby improving drying efficiency. Furthermore, the flue gas flow channels inside the heat exchange tubes 2011 not only fully utilize the waste heat of the flue gas for efficient energy use but also ensure a stable supply of heat to the water absorption assembly, guaranteeing that the dehydration unit 201 can efficiently restore its water absorption capacity after the water absorption assembly becomes saturated. These characteristics enhance the operational efficiency and stability of the entire gas drying and dehydration system.

[0043] In a preferred embodiment, the heat exchange tube 2011 is designed with a spiral structure. This spiral design has significant advantages: on the one hand, it greatly increases the heat transfer area between the heat exchange tube 2011 and the flue gas and water absorption assembly, allowing more heat to be exchanged between them; on the other hand, it extends the heat transfer time, thereby allowing the waste heat of the flue gas to be utilized more fully and effectively improving the drying effect on the water absorption assembly.

[0044] The improved drying effect ensures that the water absorption component can quickly restore its water absorption capacity, guaranteeing the continuous and stable operation of the dehydration unit 201. Furthermore, the overall dehydration efficiency of the system is further improved, providing strong support for the efficient drying and dehydration of gas, ultimately enhancing the quality of subsequent gas utilization.

[0045] like Figure 1 As shown, in a preferred embodiment, the humidity monitoring and control device 3 uses a capacitive humidity sensor 301 as the humidity monitoring component and an electric valve 302 as the actuator to control the opening and closing state of the branch. The capacitive humidity sensor 301 has an extremely fast response speed and can sensitively sense changes in the humidity of the gas, monitoring the humidity of the gas at the outlet of each dehydration unit 201 in real time and accurately.

[0046] If the humidity of the gas at the outlet of a dehydration unit 201 exceeds a preset threshold, the capacitive humidity sensor 301 will quickly transmit a signal to the control system. Upon receiving the signal, the control system immediately controls the electric valve 302 to close the branch containing the dehydration unit 201 with excessive humidity, while simultaneously opening another branch to start the standby dehydration unit 201. This ensures the continuous and stable operation of the gas drying and dehydration process, effectively avoiding poor dehydration results due to untimely humidity monitoring. The preset threshold is set according to actual conditions, with the saturation of the water absorption component of the operating dehydration unit 201 as a key benchmark. For example, the gas humidity value corresponding to 80%-90% of the saturated adsorption capacity of the water absorption component allows the system to switch to the standby dehydration unit 201 in advance, preventing poor dehydration results due to untimely humidity monitoring and ensuring that the gas consistently meets the humidity requirements for subsequent use throughout the entire drying and dehydration process.

[0047] like Figure 1 As shown, in a preferred embodiment, a mixed gas temperature sensor 101 is installed on the conveying pipeline of the gas conveying and diversion device 1 to monitor the gas temperature. This design has two important functions: First, operators can judge the operating status of the system based on temperature changes. Once abnormal temperature fluctuations occur, potential faults can be detected in time, such as whether there is a safety risk caused by local overheating, thereby ensuring system safety. Second, temperature data can provide a reference for subsequent dehydration, waste heat utilization, and other processes, facilitating the optimization of system operating parameters.

[0048] After the gas flows through the temperature sensor 101, the system will split it into two branches, which are respectively connected to the two dehydration units 201 in the dehydration device 2, thus making full preparations for the subsequent dehydration operation.

[0049] In a preferred embodiment, the water vapor emission device 5 includes an exhaust pipe connected to the dehydration unit 201. During the drying process, excess water vapor evaporated inside the dehydration unit 201 is discharged into the outside air through the exhaust pipe. A one-way valve is provided at the outlet of the exhaust pipe to effectively prevent outside air from flowing back into the system and maintain a stable dry environment inside the dehydration unit 201. This not only ensures the drying effect of the vermiculite 2012, enabling it to continuously and efficiently adsorb water vapor from the gas, but also prevents humid outside air from mixing into the gas, ensuring the dryness of the gas and providing a reliable guarantee for its subsequent utilization.

[0050] In a preferred embodiment, the outer shell of the dehydration unit 201 is made of thermal insulation material. This material effectively reduces heat loss, allowing more heat to concentrate within the dehydration unit 201 when the heat exchange component utilizes waste heat from the flue gas to dry the water absorption component. This improves waste heat utilization efficiency, reduces energy consumption, maintains a high temperature within the unit, accelerates moisture evaporation from the water absorption component, and enables it to regain its water absorption capacity more quickly. This enhances the working efficiency of the dehydration unit 201 and ensures the stable and efficient operation of the gas drying and dehydration system.

[0051] In a preferred embodiment, a flue gas waste heat inlet temperature sensor 401 is installed at the connection point between the waste heat recovery device 4 and the gas recovery device 8 at the flue gas outlet. This sensor measures the temperature of the flue gas entering the heat exchange components of the dehydration unit 201. A flue gas waste heat outlet temperature sensor 402 is installed at the flue gas outlet end of the heat exchange components of the dehydration unit 201. In this embodiment, these two sensors play a crucial role. The flue gas waste heat inlet temperature sensor 401 assesses the quality of the waste heat, providing data for automated system control, optimizing system operation, and monitoring the status of the gas recovery device 8 to ensure system safety. The flue gas waste heat outlet temperature sensor 402 measures the waste heat utilization efficiency, providing a basis for system feedback and adjustment, and reflecting the operating status of the dehydration unit 201 by monitoring its temperature anomalies. The two sensors work together to help the system efficiently utilize flue gas waste heat and operate stably.

[0052] In a preferred embodiment, a steam emission temperature sensor 501 is installed in the exhaust pipe of the steam emission device 5 between the dehydration unit 201 and the outlet check valve. This sensor can indirectly reflect the drying status of the dehydration unit 201; abnormally high or low temperatures indicate over-drying or under-drying, respectively, requiring corresponding adjustments. It can also assess system operating efficiency; large temperature fluctuations necessitate troubleshooting and optimization. Furthermore, it ensures system safety; abnormally high temperatures pose safety hazards, and alarms when thresholds are exceeded ensure system stability.

[0053] The working principle of this utility model is as follows:

[0054] The mixed gas enters the gas conveying and diversion device 1 through the mixed gas inlet 6. The mixed gas temperature sensor 101 on the conveying pipeline monitors the temperature in real time, providing data support for system safety and subsequent processes. The gas is then diverted to two dehydration units 201 of the dehydration device 2, where vermiculite 2012 adsorbs water vapor to reduce humidity. The capacitive humidity sensor 301 of the humidity monitoring and control device 3 monitors the gas humidity at the outlet of the dehydration unit 201 in real time. When the humidity exceeds the standard, the control system controls the electric valve 302 to switch branches, ensuring continuous and stable dehydration. When the dehydration unit 201 switches, the waste heat utilization device 4 connects the heat exchange components of the water-saturated unit to the flue gas outlet of the gas utilization device 8. At this time, the flue gas waste heat inlet temperature sensor 401 monitors the temperature of the incoming flue gas. The flue gas passes through the spiral heat exchange tube 2011, fully transferring waste heat to dry the vermiculite 2012. Then, the flue gas waste heat outlet temperature sensor 402 monitors the temperature of the discharged flue gas. The water vapor generated during drying is discharged through the water vapor emission device 5. The water vapor emission temperature sensor 501 in the device monitors the water vapor temperature, and its outlet check valve maintains the drying environment of the dehydration unit 201. The shell of the dehydration unit 201 is made of heat-insulating material to improve the waste heat utilization efficiency. The two dehydration units 201 work alternately to provide qualified gas to the gas utilization device 8 in a cycle, which is then output from the dried gas outlet 7.

[0055] This invention, through the coordinated operation of the aforementioned devices, achieves an automatic switching function for drying and dehydrating mixed gas based on flue gas waste heat. It effectively solves the problem of drying and dehydrating high-humidity gas and has advantages such as energy saving, environmental protection, and low cost. It meets the gas drying requirements for coal mine gas utilization and provides strong support for the efficient utilization of low-concentration gas in coal mines.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model and are not intended to limit it. Although this utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this utility model without departing from the spirit and scope of the technical solutions of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. An automatic switching type blended gas drying and dehydration system based on flue gas waste heat, characterized in that, include: The gas conveying and diversion device (1) is configured to convey the mixed gas through a conveying pipeline and divert it into two branches; The dehydration device (2) includes at least two dehydration units (201). Each dehydration unit (201) is provided with a water absorption component for removing water vapor from the gas and a heat exchange component for drying the water absorption component when it is saturated with water. Each dehydration unit (201) is connected to the two branches one by one. Humidity monitoring and control device (3) is provided at the outlet of each dehydration unit (201) to monitor the humidity of the gas in real time; and controls the opening and closing status of the branch based on the monitoring results. When the humidity of the gas at the outlet of a certain dehydration unit (201) exceeds the preset threshold, the branch where the dehydration unit (201) is located is closed, and another branch is opened at the same time. When the dehydration unit (201) is switched, the waste heat utilization device (4) connects the heat exchange component of the water-saturated dehydration unit (201) to the flue gas outlet of the gas utilization device (8) so as to use the waste heat of the flue gas to dry the water absorption component. A water vapor emission device (5) is connected to the dehydration unit (201) and is used to discharge excess water vapor generated during the drying process into the external atmosphere.

2. The automatic switching type blended gas drying and dehydration system based on flue gas waste heat according to claim 1, characterized in that, The water-absorbing component in the dehydration device (2) is made of porous material.

3. The automatic switching type blended gas drying and dehydration system based on flue gas waste heat according to claim 2, characterized in that, The porous material is vermiculite with a porous structure (2012).

4. The automatic switching type blended gas drying and dehydration system based on flue gas waste heat according to claim 1, characterized in that, The heat exchange assembly includes multiple heat exchange tubes (2011) arranged in parallel. The tube walls of the heat exchange tubes (2011) are thermally conductive, and their internal channels are used for flue gas circulation.

5. The automatic switching type blended gas drying and dehydration system based on flue gas waste heat according to claim 4, characterized in that, The heat exchange tube (2011) has a spiral structure to increase the area and time of heat transfer between the heat exchange tube (2011) and the flue gas and water absorption components, thereby improving the drying effect.

6. The automatic switching type blended gas drying and dehydration system based on flue gas waste heat according to claim 1, characterized in that, The humidity monitoring component in the humidity monitoring and control device (3) is a capacitive humidity sensor (301).

7. The automatic switching type blended gas drying and dehydration system based on flue gas waste heat according to claim 1, characterized in that, The actuator for controlling the opening and closing state of the branch in the humidity monitoring and control device (3) is an electric valve (302).

8. The automatic switching type blended gas drying and dehydration system based on flue gas waste heat according to claim 1, characterized in that, The gas conveying and diversion device (1) is equipped with a mixed gas temperature sensor (101) on the conveying pipeline to monitor the gas temperature.

9. The automatic switching type blended gas drying and dehydration system based on flue gas waste heat according to claim 1, characterized in that, The water vapor emission device (5) includes an exhaust pipe connected to the dehydration unit (201), and a one-way valve is provided at the outlet of the exhaust pipe to prevent backflow of outside air.

10. The automatic switching type blended gas drying and dehydration system based on flue gas waste heat according to any one of claims 1-9, characterized in that, The outer shell of the dehydration unit (201) is made of heat-insulating material to reduce heat loss and improve waste heat utilization efficiency.

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