A device and method for deep decomposition and adsorption of SF6 gas in a limited space

Abstract

A device and method for deep decomposition and adsorption of SF6 gas in a limited space, the device comprising: a particle filter, a catalytic adsorption tower, a heat exchanger, a neutralization adsorption device, a first oil-free air suction pump, a molecular sieve adsorption bed, and a control system; the particle filter is used to filter and inhale the atmosphere mixed with SF6, and block the ash particles and other substances in the environment; the catalytic adsorption tower is connected to the particle filter, and is used to heat and decompose the SF6 mixed in the air in the catalytic adsorption tower and adsorb the decomposed products; the heat exchanger is connected to the catalytic adsorption tower; the neutralization adsorption device is connected to the heat exchanger, and neutralizes and absorbs the acidic substances generated by the catalytic adsorption tower; the first oil-free air suction pump is connected to the neutralization adsorption device to provide power for gas flow; the molecular sieve adsorption bed is used to adsorb the residues that are not suitable for discharge before discharge; the control system is used to control the temperature of the catalytic adsorption tower, and the temperature in the catalytic adsorption tower is controlled between a first set value and a second set value by using the "flying temperature" of the catalytic adsorption tower.

Description

Technical Field

[0001] The present invention belongs to the technical field of power equipment operation and maintenance safety assurance, and more specifically, relates to a device for deep decomposition and adsorption of SF6 gas in a limited space. Background Art

[0002] Since the 20th century, countries around the world have been developing science and technology and economy at an unprecedented speed, resulting in increasingly prominent environmental problems and resource scarcity problems. Among them, global warming caused by the greenhouse effect is one of the typical problems. SF6, as one of the main greenhouse gases stipulated in the Paris Agreement and the Kyoto Protocol, is a greenhouse gas that can remain in the atmosphere for up to 3,200 years, and its GWP (Global Warming Potential) is about 23,900 times that of the same amount of CO2. Nowadays, SF6, as an insulating arc-extinguishing gas that must be used in high-voltage, ultra-high-voltage and ultra-high-voltage electrical appliances, is one of the most important materials in my country's high-voltage power transmission and transformation and electrical appliance manufacturing fields. According to relevant statistics, about 8,100 tons of SF6 (from the power industry) are emitted worldwide each year, equivalent to 200 million tons of MtCO2e (Metric tons of carbon dioxide equivalent)

[0003] In my country, SF6 gas is usually used as an insulating and arc-extinguishing medium gas for electrical appliances such as high-voltage switches, transformers, and high-voltage transmission and transformation pipelines. It is widely used in power operation and electrical manufacturing industries. The use of SF6 increases year by year at a rate of 8,000 tons per year, and does not include the cumulative amount of SF6 repeatedly used by electrical manufacturing companies.

[0004] Whether it is from the operation and maintenance of electrical appliances or the manufacturing process, leakage is inevitable. After leakage into the atmosphere around the appliances and the manufacturing workshop, it mixes with the atmosphere and dilutes and spreads rapidly. It is impossible to recycle SF6 by recycling methods because it is mixed with a large amount of air, and the recycling and storage volume is very large, which is very uneconomical.

[0005] In addition, some equipment manufacturers use two methods of collecting and purifying SF6: one is to use high-pressure refrigeration to liquefy SF6 and then separate the air, but this method requires that the SF6 content in the mixed gas cannot be less than 70%, which is extremely unlikely. The second is to use modern permeable membrane technology to separate SF6 from air. This method also requires that the SF6 content cannot be less than 30%, and also requires constant temperature and pressure. As far as leakage is concerned, it is basically unlikely that the atmosphere contains more than 30% SF6, except in confined spaces. At the same time, the permeable membrane is expensive and has a short lifespan, so it is not suitable for non-fixed places. Moreover, both methods have residual SF6 tail gas emissions. The Chinese government has issued the strategic goals of carbon peak and carbon neutrality. Carbon emission reduction of SF6 is an important task. Therefore, research on safe emission reduction of SF6 is an urgent problem to be solved.

[0006] At present, no research institute or enterprise in any country in the world has been found to have special products and applicability research on the degradation of SF6 in atmospheric atmosphere. In the domestic power industry, some experts have studied the decomposition mechanism of SF6 by simulating the decomposition of SF6 in the laboratory by arcing in a high-voltage switch, and published some papers. The research mainly decomposes SF6 by electric shock or heating in a carrier gas (such as argon) atmosphere to produce decomposition products similar to those produced by arcing in a high-voltage switch, and describes some methods of adsorption treatment of decomposition products. However, no further research has been conducted on the decomposition of SF6 in atmospheric atmosphere and the general applicability of SF6 decomposition in atmospheric atmosphere, especially the research on equipment that is simple and low-cost to operate under non-laboratory conditions. Summary of the invention

[0007] In order to solve the deficiencies in the prior art, the purpose of the present invention is to provide a SF6 gas decomposition and adsorption device in a limited space, which can decompose and adsorb SF6 gas with a concentration ranging from 1ppm to 70% in an atmospheric atmosphere, and further provide an extremely low energy consumption catalytic adsorption tower structure for completely decomposing and adsorbing SF6 within a certain temperature range (600°C to 800°C). The extremely low power consumption avoids the high energy consumption and high carbon emissions caused by transfer; no carrier gas is used, and only an oil-free pump is used to pump the atmosphere containing SF6 for decomposition and adsorption, thereby avoiding secondary pollution caused by oil mist from other additional equipment; the generation of secondary pollutants and secondary toxic substances in the device process is solved, and the performance indicators meet the national standard "Occupational Exposure Limits for Harmful Factors in the Workplace"; the reuse of failed catalyst solid waste and the efficient treatment of hazardous waste are solved, and harmless emissions are truly achieved.

[0008] The present invention adopts the following technical scheme. The first aspect of the present invention provides a device for deep decomposition and adsorption of SF6 gas in a limited space, comprising: a particle filter, a catalytic adsorption tower, a heat exchanger, a neutralization adsorption device, a first oil-free air suction pump, a molecular sieve adsorption bed, and a control system; the particle filter is used to filter the air mixed with SF6 when it is inhaled, and block the ash particles and other substances in the environment; the catalytic adsorption tower is connected to the particle filter, and is used to heat and decompose the SF6 mixed in the air in the catalytic adsorption tower, and adsorb the decomposed product through the special adsorbent filled in the catalytic adsorption tower; the heat exchanger is connected to the The catalytic adsorption tower and the heat exchanger cool down the high-temperature gas discharged from the catalytic adsorption tower; the neutralization adsorption equipment is connected to the heat exchanger to neutralize and absorb the acidic substances that are not completely adsorbed in the catalytic adsorption tower; the first oil-free suction pump is connected to the neutralization adsorption equipment to provide power for the gas flow; the molecular sieve adsorption bed is used to adsorb the residues that are not suitable for discharge before discharge; the control system is used to control the temperature of the catalytic adsorption tower, and the temperature in the catalytic adsorption tower is controlled between the first set value and the second set value by using the "flying temperature" of the catalytic adsorption tower; the control system is also used to control and operate the interrelated parameters of the various components of the decomposition adsorption device.

[0009] Preferably, the catalytic adsorption tower comprises: an air inlet, a pull rod, a barrel body and a material seat, and the outer side of the barrel body is an annular air supply channel.

[0010] Preferably, the compressed air is connected to the control system, and when it is higher than a first set value, air supply cooling to the barrel of the catalytic adsorption tower is started; the control system dynamically controls the ventilation volume of the compressed air based on the temperature rise caused by the "flying temperature" on the catalytic adsorption tower.

[0011] Preferably, the neutralization and adsorption equipment comprises: a solid alkali neutralization tower and a liquid alkali neutralization and adsorption tower;

[0012] The solid alkali neutralization tower is arranged between the heat exchanger and the first oil-free suction pump, and is used to pre-neutralize some decomposed acidic substances that are not completely adsorbed by the catalyst after decomposition and adsorption in the solid alkali;

[0013] The liquid alkali neutralization adsorption tower is arranged between the first oil-free suction pump and the molecular sieve adsorption bed to completely eliminate the acidic substances generated after SF6 is decomposed and adsorbed.

[0014] Preferably, the liquid alkali neutralization adsorption tower is provided with a stirring device to improve the neutralization adsorption speed and effect.

[0015] Preferably, the SF6 gas deep decomposition and adsorption device in a limited space further comprises: a second oil-free air suction pump;

[0016] The second oil-free suction pump is connected to the molecular sieve adsorption bed and is used to provide power for the gas to flow in the molecular sieve adsorption bed.

[0017] Preferably, the SF6 gas deep decomposition and adsorption device in a limited space further comprises: an exhaust gas measurement chamber;

[0018] The tail gas measuring chamber is connected to the outlet end of the second air suction pump.

[0019] Preferably, the tail gas measurement chamber is equipped with detectors for HF, SO2, H2S, SF4, substances produced after SF6 decomposition, and residual SF6 that cannot be decomposed, and the instrument measurement values ​​are sent to the control system.

[0020] Preferably, the SF6 gas deep decomposition and adsorption device in a limited space is a vehicle-mounted and movable equipment in a limited space. It can be moved with the vehicle to a scene where SF6 gas decomposition and adsorption is required, and can also be moved and placed in a limited space to a required working point.

[0021] The second aspect of the present invention provides a method for deep decomposition and adsorption of SF6 gas in a limited space, using the device for deep decomposition and adsorption of SF6 gas in a limited space, comprising the following steps:

[0022] Step 1, air containing SF6 enters the SF6 gas deep decomposition adsorption device in a limited space and is filtered at the particle filter;

[0023] Step 2, the gas filtered in step 1 enters the catalytic adsorption tower, and the SF6 mixed in the air is thermally degraded in the catalytic decomposition tower. The "flying temperature" phenomenon of the catalytic adsorption tower is used to maintain the temperature required for the catalytic adsorption tower to continue working without adding power consumption, and the temperature in the catalytic adsorption tower is controlled between the first set value and the second set value;

[0024] Step 3, sending the gas flow with a higher temperature after passing through the catalytic absorption tower process in step 2 to a heat exchanger, and then to a neutralization adsorption device to neutralize and absorb the acidic substances that have not been completely adsorbed in the catalytic absorption tower;

[0025] Step 4, continue to flow through the molecular sieve adsorption bed to adsorb the fluoride and sulfide that failed to be adsorbed in the previous steps, and adsorb all harmful substances;

[0026] In step 5, the exhaust gas emission will be monitored by real-time online detection method, and the data will be sent to the control system for comparison and display, judgment and control.

[0027] Preferably, step 1 comprises: using one or more SF6 content sensors in the environment, when the SF6 content is not detected or is less than the set SF6 content value, the device is in a standby state, and when the SF6 content is detected to reach the set value, the device automatically starts; entering the catalytic adsorption tower heating preparation state, when the catalytic adsorption tower reaches the catalytic temperature; automatically starting the heat exchanger, the spray adsorption tower, the first oil-free air suction pump and the second oil-free air suction pump in sequence.

[0028] Preferably, step 3 comprises: sending the higher temperature gas flow after passing through the catalytic absorption tower process in step 2 into a heat exchanger to cool it down to below 100°C, and then entering a solid alkali neutralization tower to neutralize the acidic substances that have not been completely adsorbed after catalysis in the alkali neutralization tower, and sending the gas that has passed through the solid alkali neutralization tower into a liquid alkali neutralization adsorption tower.

[0029] Preferably, in step 3, the liquid alkali neutralization adsorption tower is a liquid alkali stirring neutralization tower, and the liquid alkali stirring neutralization tower is equipped with a pH sensor for real-time detection of the pH value of the alkali solution.

[0030] Preferably, in step 4, a second oil-free suction pump is used between the molecular adsorption bed and the tail gas measurement chamber to increase the inlet and outlet pressure difference of the molecular sieve adsorption bed through the suction force of the pump, so that the gas flows smoothly through the molecular sieve adsorption bed.

[0031] Preferably, in step 5, the exhaust gas measurement chamber is equipped with a detector for HF, SO2, H2S, SF4, the main substances produced after the decomposition of SF6, and residual SF6 that cannot be decomposed. The instrument measurement value is sent to the PLC controller and compared with the preset upper limit value. When the limit value is exceeded, an alarm of a high content of a certain substance appears on the industrial control computer, and the machine automatically shuts down. At the same time, a prompt pops up: information such as catalyst failure, spray saturation, molecular sieve adsorption saturation, etc., to give a judgment on maintenance or replacement of parts.

[0032] Compared with the prior art, the beneficial effects of the present invention include at least:

[0033] 1) This patented technical solution solves the problem that SF6 leaked and diffused into the atmosphere is difficult to recover and extract. The recovery and extraction of SF6 leaked and diffused into the atmosphere is very difficult and costly, and it cannot be stored. More importantly, it solves the serious greenhouse effect caused by the leakage and diffusion of SF6 in the atmosphere, and solves the problem that SF6 takes 3,000 to 5,000 years to be naturally degraded in the atmosphere.

[0034] 2) This patented technical solution solves the problem of large amounts of energy consumption required for incineration and degradation of SF6. The energy consumption required for heating and degradation of SF6 in this patented technical solution is extremely low. The device only needs to heat the catalytic adsorption tower to 600--800℃ and no longer needs electricity consumption. It only needs to consume extremely low electricity to maintain the operation of electrical control and oil-free suction pumps, and these components only consume 2-3kW of electricity. The device's electricity consumption is converted into carbon emissions for power generation, which is only equivalent to the energy consumption of a household cabinet air conditioner, which is far less than the energy consumption of uninterrupted industrial equipment. The operating cost is extremely low.

[0035] 3) The device consumes low amounts of catalysts. The device achieves a catalyst consumption ratio of SF6:catalyst=1.2-1.5:1. The emission of 1kg SF6 is equivalent to 23,900kg CO2 (about 24 tons). The carbon emission cost is quite high. The cost of 1kg catalyst is less than RMB 80, which is equivalent to 1 / 24 of the carbon emission cost.

[0036] 4) After the device decomposes and adsorbs SF6, no secondary pollution or toxic substances are generated. The catalyst after decomposition and adsorption can be reused in construction, battery electrode material addition, and other metal alloy material additives. The exhaust gas emissions meet the occupational exposure limit standards for harmful factors in the workplace.

[0037] 5) The device is suitable for existing indoor and outdoor, underground substations, electrical manufacturing workshops, test halls of electrical testing institutes and other places where SF6 gas is used. The device is small in size, does not require installation, can be moved and placed, and enters working state as soon as it is turned on.

[0038] 6) The device has a high degree of automation, and all operating parameters and data can be monitored remotely. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 is a flow chart of the present invention;

[0040] Figure 2 A front view of a device for deep decomposition and adsorption of SF6 gas in a limited space provided by the present invention;

[0041] Figure 3 A rear view of a device for deep decomposition and adsorption of SF6 gas in a limited space provided by the present invention;

[0042] Figure 4 A structural diagram of a catalytic adsorption tower of a device for deep decomposition and adsorption of SF6 gas in a limited space provided by the present invention.

[0043] In the figure:

[0044] 1-particle filter; 2-catalytic adsorption tower; 3-heat exchanger; 4-solid alkali neutralization tower; 5-first oil-free air suction pump; 6-liquid alkali neutralization adsorption tower; 7-molecular sieve adsorption bed; 8-second oil-free air suction pump; 9-exhaust gas measurement chamber; 10-annular air supply channel; 20-pull rod; 30-barrel body; 40-material seat. DETAILED DESCRIPTION

[0045] The present application is further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present application.

[0046] like Figure 1 , 2As shown in Figure 3, Example 1 of the present invention provides a device for deep decomposition and adsorption of SF6 gas in a limited space, comprising: a particulate filter 1, a catalytic adsorption tower 2, a heat exchanger 3, a solid alkali neutralization tower 4, a first oil-free air suction pump 5, a liquid alkali neutralization adsorption tower 6, a molecular sieve adsorption bed 7, a second oil-free air suction pump 8 and an exhaust gas measurement chamber 9.

[0047] It can be understood that the limited space referred to in the present invention refers to the application scenario of the SF6 gas deep decomposition and adsorption device. In engineering practice, the present invention is applicable to any situation where SF6 gas may leak and be discharged and SF6 gas decomposition and adsorption is required. The main situations are introduced in an enumerated but not exhaustive manner:

[0048] 1) There are defects in the sealing of the materials or joints of the high-voltage electrical appliances. After inflation, due to the relationship between pressure and temperature, micro-leakage occurs, generally within 10-100ppm, of course, there are larger cases. This is a hidden, long-term, and difficult-to-find leak. It is not easy to detect the leak point with a leak detector. Usually, after a period of operation, SF6 is deposited around the electrical appliances, especially in the lower part of the electrical appliances, and slowly diffuses into the surrounding environment. There is a certain degree of harm to the operation and maintenance personnel.

[0049] 2) When the on-site electrical equipment is overhauled due to a fault, the SF6 in the gas chamber is first recovered, but the recovery is impossible to be complete. When the gas chamber is opened, the residual SF6 inside is discharged into the surrounding environment. At the same time, the operation during the SF6 recovery process will also cause uncontrollable leakage. In addition, the work of calibrating the density meter will also be discharged into the surrounding environment. The most serious situation is that there is a sudden failure on site and rapid repair is required, but there is no recovery equipment on site. In this case, it is very likely that a large amount of gas will be considered to be discharged into the surrounding atmosphere.

[0050] 3) In electrical manufacturing workshops, according to the electrical manufacturing process, after SF6 is filled and high-voltage testing is performed, the gas is recovered and reused. The connecting pipes and joints are frequently replaced, and the recovery is not thorough. The actual concentration in the workshop is relatively high. Currently, most of them are discharged to the atmosphere through ventilation.

[0051] 4) High-voltage electrical appliance testing institutes conduct the most stringent experiments on electrical appliance quality. Some products with poor quality control often produce extreme discharge during high-voltage testing, causing the gas chamber to be damaged and leaking a large amount of SF6 gas. The gas is also mixed with SF6 decomposition products, which has a relatively large impact on personnel and the environment.

[0052] 5) With the requirements of economic development, underground switch stations, substations, and GIL corridors have been newly built in some places where ground is relatively scarce. These are all closed and limited spaces, which seriously affect the safety of operation and maintenance personnel and the environment.

[0053] 6) Other places and situations where SF6 is produced, used and processed, etc.

[0054] The particle filter 1 is used to filter the air mixed with SF6 when inhaling it, blocking the ash particles and other substances in the environment, and preventing these substances from entering the catalytic adsorption tower 2 and affecting the catalytic function and efficiency.

[0055] The catalytic adsorption tower 2 is used to heat and decompose the SF6 mixed in the air sucked in the catalytic adsorption tower 2 and adsorb the decomposed products through the special adsorbent filled in the catalytic adsorption tower. This part is one of the core parts of the device function, such as Figure 2 shown.

[0056] In a preferred but non-limiting embodiment of the present invention, Figure 4 As shown, the catalytic adsorption tower includes: an air inlet, a pull rod 20, a barrel 30 and a material seat 40, and the outer side of the barrel 30 is an annular air supply channel 10. The inventor creatively invented the use of compressed air to supply air to the catalytic adsorption tower in an annular manner between the furnace and the catalytic adsorption tower, which led to a major improvement of the present invention over the prior art and the beneficial technical effect achieved. When compressed air is used to supply air to the outside of the catalytic adsorption tower in an annular manner, how to achieve the best control effect. The technical difficulties at least include: in view of the characteristics of the "flying temperature" phenomenon itself, after reading the internal temperature of the catalytic adsorption tower, the control effect of only using the temperature as a variable for real-time control is not ideal, and there is hysteresis, and it is difficult to achieve a balance between ensuring that the temperature runs within a reasonable range, not wasting the heat of the fly-away temperature, and reducing the power consumption of the air compressor. Only by achieving a good balance can the beneficial technical effect of the present invention of efficiently treating SF6 catalytic adsorption while reducing energy consumption be more prominent. This is because too small a compressed air ventilation volume is likely to cause the temperature to exceed the working range after the fly-away temperature, and too large a ventilation volume is likely to waste energy on the one hand, and on the other hand, it is likely to cause the temperature to fall out of the working range.

[0057] After a lot of research and experiments, the inventors obtained a better control method for the balance of the three, which is expressed as the following formula:

[0058]

[0059] Where:

[0060] V cda Indicates the compressed air ventilation volume per unit time, which is used to control the temperature range of catalytic adsorption between 600℃ and 800℃.

[0061] k represents the heat dissipation adjustment coefficient of the catalytic adsorption tower, which is used to adjust the proportion of catalytic adsorption towers with different heat dissipation conditions, for example but not limited to, high temperature resistant stainless steel catalytic adsorption towers and catalytic adsorption towers with different heat dissipation surface areas can be used, and the heat dissipation adjustment coefficient k of the catalytic adsorption tower is used for adjustment, for example but not limited to setting different specifications of equipment during the operation test;

[0062] v gas Indicates the volume of SF6 gas passing through the catalytic adsorption tower per unit time, used to indicate the flow rate of the gas to be catalytically adsorbed, and is controlled by the first oil-free suction pump.

[0063] V tower It indicates the space volume in the catalytic adsorption tower used for catalytic adsorption of SF6 gas.

[0064] t represents the real-time temperature inside the catalytic adsorption tower, which is read in real time by the temperature sensor inside the catalytic adsorption tower for closed-loop control.

[0065] C sf6 It indicates the percentage content of SF6 in the SF6 gas introduced into the catalytic adsorption tower. It is worth noting that the present invention is directed to the decomposition and adsorption of SF6 gas with a concentration ranging from 1 ppm to 70%, i.e., C sf6 The value range of

[0066] η1 represents the first weight coefficient, η2 represents the second weight coefficient, and the following relationship is satisfied:

[0067] More preferably, the inventors have also creatively invented a dual structure of using compressed air between the furnace and the catalytic adsorption tower to supply air in an annular manner to the catalytic adsorption tower and to supply air in an annular manner to the catalyst in the catalytic adsorption tower, so as to achieve a structure in which air is supplied to the inside and outside of the catalytic adsorption tower for cooling when the temperature rises. The air supply is controlled by a temperature sensor, which ensures the temperature of 600--800°C required by the catalytic adsorption tower on the one hand, and evenly supplies air during the temperature rise, and evenly dissipates heat and cools down, so that the catalytic adsorption tower always maintains normal operation within the set temperature range. When the present invention uses compressed air to control the temperature of the temperature rise, it only needs to adjust the parameters in the formula during the operation test to obtain the beneficial technical effects described in the present invention, and the control strategy is placed in the control program, which greatly improves the applicability of the present invention.

[0068] The heat exchanger 3 is used to cool the high-temperature gas coming from the catalytic adsorption tower 2 to a temperature that does not affect the operation of the rear-end components.

[0069] The solid alkali neutralization tower 4 is used to pre-neutralize some decomposed acidic substances that are not completely adsorbed by the catalyst after decomposition and adsorption in solid alkali, so that the acidic substances in the gas are fully reduced.

[0070] The first oil-free suction pump 5 is used to provide power for the gas to circulate in the SF6 gas deep decomposition adsorption device. More specifically, the gas circulation requires a certain amount of power. The gas can flow in the SF6 gas deep decomposition adsorption device in the limited space through the suction and then compression of the first oil-free suction pump 5. At the same time, the speed of the pump determines the processing speed of the SF6 gas deep decomposition adsorption device in the limited space. The oil-free pump is selected to avoid the oil pollution of the pump lubricating oil to the gas pipeline and the discharged gas.

[0071] The liquid alkali neutralization and adsorption tower 6 is used to completely eliminate the acidic substances produced after SF6 is decomposed and adsorbed, and further processed by the liquid alkali neutralization and adsorption tower 6. In addition, due to the application scenario of the SF6 gas deep decomposition and adsorption device in a limited space, the SF6 content is uncertain. If the content is large, there will be more decomposition products, and the previous solid alkali may not be able to be completely neutralized. During the design and testing process of the SF6 gas deep decomposition and adsorption device in a limited space, a liquid alkali neutralization and adsorption tower is added and a stirring device is installed, which further effectively enhances the neutralization and adsorption speed and effect to achieve a safe emission effect.

[0072] The molecular sieve adsorption bed 7 is used to adsorb residues that are not suitable for discharge. More specifically, after neutralization and adsorption with liquid alkali, some gases may not be able to fully contact with the alkali solution, and a very small amount of low-fluorine substances may leak out during the spraying process and flow out with the airflow. At this time, the molecular sieve can play a role of re-adsorption, and mixed with calcium oxide to further neutralize and adsorb residual acidic substances and unknown trace harmful substances, so that the discharged gas can meet or exceed the national emission standards.

[0073] The second oil-free air suction pump 8 is used to provide power for the gas to flow in the molecular sieve adsorption bed 7. More specifically, a certain pressure difference is required to make the gas flow in the above-mentioned molecular sieve adsorption bed. The molecular sieve is granular. Although there is a certain gap between the molecular sieves of the molecular sieve adsorption bed, there is a certain air resistance. At this time, the second oil-free air suction pump 8 provides a certain suction force at the outlet end of the molecular sieve adsorption bed, forming a certain pressure difference between the inlet and the outlet, so that the airflow can pass through the molecular sieve adsorption bed smoothly without causing air blockage.

[0074] The exhaust gas measuring chamber 9 is connected to the outlet end of the second suction pump, and the suction pump outlet gas with a certain exhaust pressure is discharged into the exhaust gas measuring chamber, creating a flow pool type instrument measurement environment. After the pump outlet airflow with a certain pressure is diffused in the measuring chamber, the pressure is slightly higher than the atmospheric pressure, which can not only discharge the gas smoothly out of the chamber, but also has a diffusion force slightly higher than the atmospheric pressure, so that the gas can smoothly enter the sensor pool of the measuring instrument, so that the instrument can smoothly detect the corresponding data.

[0075] More preferably, the tail gas measurement chamber is equipped with detectors for HF, SO2, H2S, SF4, the main substances produced after SF6 decomposition, and residual SF6 that cannot be decomposed, and the instrument measurement values ​​are sent to the PLC controller.

[0076] It is worth noting that the particle filter 1, the catalytic adsorption tower 2, the heat exchanger 3, the solid alkali neutralization tower 4, the first oil-free air pump 5, the liquid alkali neutralization adsorption tower 6, the molecular sieve adsorption bed 7, the second oil-free air pump 8 and the tail gas measurement chamber 9 are the main parts for realizing the core functions of the SF6 gas deep decomposition and adsorption device in a limited space, that is, the deep decomposition and adsorption functions. As a further contribution of the prior art of the present invention, the SF6 gas deep decomposition and adsorption device in a limited space is equipped with an automatic control part, that is, a control system, such as but not limited to a PLC controller, as well as an information data remote transmission part, a movable rack part, forming a device that can not only realize functional requirements but also meet on-site use, and is both convenient to install and safe and environmentally friendly.

[0077] The SF6 gas deep decomposition and adsorption device in a limited space is a vehicle-mounted and movable equipment in a limited space. It can be moved with the vehicle to a scene where SF6 gas decomposition and adsorption is required, and can also be moved and placed in a required working point in a limited space.

[0078] The second aspect of the present invention provides a method for deep decomposition and adsorption of SF6 gas in a limited space, wherein air containing SF6 is sucked into a catalytic adsorption tower through a particle filter to perform SF6 decomposition catalysis and adsorb SF6 decomposition products, specifically, comprising the following steps:

[0079] Step 1, air containing SF6 enters the SF6 gas deep decomposition adsorption device in a limited space and is filtered at the particle filter 1 to block the particulate dust in the ambient gas and prevent the particulate dust from entering the catalytic adsorption tower and reducing the efficiency.

[0080] In a preferred but non-limiting embodiment of the present invention, the monitoring data is transmitted to the PLC control system of the device through one or more SF6 content sensors in the environment, and the real-time data is displayed on the industrial computer of the system. When the SF6 content is not detected or is less than the set SF6 content value, the device is in a standby state. When the SF6 content is detected to reach the set value, the device starts to start automatically and enters the catalytic adsorption tower heating preparation state. When the catalytic adsorption tower reaches the catalytic temperature, the device enters the next step, and the air containing SF6 enters the SF6 gas deep decomposition adsorption device in the limited space and is filtered at the particle filter 1.

[0081] Furthermore, the heat exchanger, the spray adsorption tower, the first oil-free air suction pump 5 and the second oil-free air suction pump 8 are automatically started in sequence, and the mixed gas containing SF6 passes through the device according to the process, SF6 is decomposed and adsorbed, and the decomposition residues are completely absorbed.

[0082] Step 2, the gas filtered in step 1 enters the catalytic adsorption tower 2, and the SF6 mixed in the air is thermally degraded in the catalytic decomposition tower. The catalytic adsorption tower is filled with a special catalyst, and the SF6 is thermally decomposed into ions containing S and F, which are absorbed by the catalyst to generate stable fluorides and sulfides, which are also absorbed by the catalyst. The air cannot be decomposed in the catalytic adsorption tower, but the oxygen contained in the air is partially combined with fluorides and sulfides to form oxygen-containing compounds during the catalytic process. The temperature range of catalytic adsorption is between 600°C and 800°C.

[0083] As one of the most important contributions of the present invention to the prior art, SF6 is a very stable inert gas with a gemstone-like molecular structure. When it degrades at high temperatures, it releases a large amount of heat. As a result, once SF6 enters the catalytic adsorption tower, the preheating of the catalytic adsorption tower at 600--800°C will cause a temperature runaway phenomenon. Even if the catalytic adsorption tower is no longer heated, the temperature continues to rise, which is very detrimental to the safety of the catalytic adsorption tower. When the SF6 content is high, the temperature rises faster. The inventor found in the experiment that when the SF6 content is 30%, the temperature rise exceeds 1300°C, and when the SF6 content is 40%, the temperature rise exceeds 1500°C. Therefore, the inventor concluded that when the content is higher, the temperature rise is higher during the catalytic process. However, this phenomenon is not good for the catalytic adsorption tower itself, as general metal materials and stainless steel cannot withstand this temperature.

[0084] It is worth noting that one of the technical difficulties overcome by the technical solution of the present invention is that the inventor consulted articles and technical materials related to the use of catalysts to degrade gases, and found no description of the SF6 temperature rise phenomenon, but some described cooling methods, such as water mist cooling, air cooling, and spray cooling methods for the reaction tank. These methods are not suitable for the temperature rise of SF6 catalysis. On the one hand, the inventor described the SF6 use environment as a high-voltage electrical room, substation, manufacturing workshop, and test hall above. These occasions are strictly water-free, so water mist and spray are not suitable. In addition, air cooling is only for the surface of the catalytic adsorption tower. Although it has a certain effect, it is not ideal for the structural effect of placing the catalytic adsorption tower in a high-temperature furnace in this article.

[0085] After a lot of research and experiments, the inventors have found a better control method that can balance the three factors of ensuring that the temperature operates within a reasonable range, not wasting heat from overheating, and reducing the power consumption of the air compressor. It can be expressed as the following formula:

[0086]

[0087] Where:

[0088] V cda Indicates the compressed air ventilation volume per unit time, which is used to control the temperature range of catalytic adsorption between 600℃ and 800℃.

[0089] k represents the heat dissipation adjustment coefficient of the catalytic adsorption tower, which is used to adjust the proportion of catalytic adsorption towers with different heat dissipation conditions, such as but not limited to, high-temperature resistant stainless steel catalytic adsorption towers and catalytic adsorption towers with different heat dissipation surface areas may be used, and the heat dissipation adjustment coefficient k of the catalytic adsorption tower is used for adjustment, such as but not limited to setting different specifications of equipment during the operation test;

[0090] v gas Indicates the volume of SF6 gas passing through the catalytic adsorption tower per unit time, used to indicate the flow rate of the gas to be catalytically adsorbed, and is controlled by the first oil-free suction pump.

[0091] V tower It indicates the space volume in the catalytic adsorption tower used for catalytic adsorption of SF6 gas.

[0092] t represents the real-time temperature inside the catalytic adsorption tower, which is read in real time by the temperature sensor inside the catalytic adsorption tower for closed-loop control.

[0093] C sf6 It indicates the percentage content of SF6 in the SF6 gas introduced into the catalytic adsorption tower. It is worth noting that the present invention is directed to the decomposition and adsorption of SF6 gas with a concentration ranging from 1 ppm to 70%, i.e., C sf6 The value range of

[0094] η1 represents the first weight coefficient, η2 represents the second weight coefficient, and the following relationship is satisfied:

[0095]

[0096] The above formula defines the proportional relationship between the flow rate-temperature weight and the concentration weight, which is one of the core concepts of the inventor of the present invention to control the catalytic adsorption process. The air compressor is controlled based on the above-mentioned compressed air ventilation volume and weight relationship to maximize the full use of the temperature and reduce the energy consumption of the device; the above parameters can be obtained through sensors and sent to the control system of the SF6 gas deep decomposition adsorption device in a limited space to perform closed-loop control. For example, but not limited to, temperature sensors are installed inside and outside the catalytic adsorption tower, and the external sensor is used to judge the working state of the heater and is controlled by the PLC at the set temperature.

[0097] Furthermore, in order to address the high-temperature catalysis and temperature runaway phenomena, 310S high-temperature resistant stainless steel material is used to make the catalytic adsorption tower, which has a maximum temperature resistance of up to 1100°C. Combined with the described internal and external annular air supply structure, it ensures the safe operation of the equipment.

[0098] It is worth noting that the technical solution of the present invention is a significant improvement over the prior art, namely, the beneficial effects are: first, the method of using compressed air to cool the catalytic adsorption tower by annular air supply inside and outside the catalytic adsorption tower when the catalytic adsorption tower generates a temperature spike, which avoids the water explosion phenomenon caused by the sudden addition of normal temperature or low temperature water or water mist to the high-temperature metal surface when using water or water mist for cooling, as well as the unsafe factor of increasing the ambient humidity by rapidly generating a large amount of water vapor; second, the characteristic of temperature spike is reasonably applied, so that the equipment does not need to consume electricity to heat the catalytic adsorption tower during operation, but only needs to consume electricity when preheating the equipment before operation, which effectively reduces energy consumption. This invention has great differences and advantages over the existing catalytic degradation methods.

[0099] In step 3, the gas flow with a higher temperature after passing through the catalytic absorption tower process in step 2 is sent to a heat exchanger to be cooled to less than 100° C., and then enters a solid alkali neutralization tower to neutralize the acidic substances that have not been completely adsorbed after catalysis in the alkali neutralization tower.

[0100] As one of the improvements and contributions of the present invention to the prior art, the selection of solid alkali neutralization has the following characteristics:

[0101] 1. The gaps between solid granular alkali are large, which is conducive to the flow of gas, with small resistance and no effect on speed.

[0102] 2. Solid alkali has strong neutralization ability and is set as the first stage to carry out most of the acid-base neutralization. It serves as the first barrier for subsequent treatment, reduces the pressure of subsequent treatment, and is also conducive to the treatment of large amounts of gas.

[0103] In a preferred but non-limiting embodiment of the present invention, a first oil-free air pump is used to provide power for the gas to circulate in the device. More specifically, the first oil-free air pump plays a suction role on the one hand, providing suction power for the gas inflow at the front end of the pump, and at the same time provides a certain gas pressure for the gas to enter the liquid alkali neutralization tower in the subsequent step, so that the gas after catalytic adsorption flows smoothly into the stirring liquid alkali neutralization tower. It is worth noting that the oil-free lubricated air pump is selected to avoid the oil pollution generated by the oil pump from polluting the alkali solution and subsequent pipes, parts, etc., which effectively avoids the possibility of additional pollution.

[0104] The gas passing through the solid alkali neutralization tower is sent to the liquid alkali neutralization adsorption tower. Specifically, the liquid alkali neutralization adsorption tower is a liquid alkali stirring neutralization tower, which is used to stir and alkaline wash the gas pressed by the oil-free pump under alkali liquid to neutralize the acidic substances in the process to the greatest extent to meet the emission requirements.

[0105] In a preferred but non-limiting embodiment of the present invention, a pH sensor is installed in the liquid alkali stirring neutralization tower to detect in real time whether the pH value of the alkali solution meets the design requirements, so as to determine whether alkali needs to be added.

[0106] In another preferred but non-limiting embodiment of the present invention, a liquid alkali stirring and neutralization tower is equipped with a alkali liquid level sensor to ensure the necessary liquid volume of the alkali liquid for operation, so that the liquid level is neither lower than nor higher than the controlled liquid level of the alkali liquid.

[0107] In another preferred but non-limiting embodiment of the present invention, a temperature sensor is installed in the liquid alkali stirring neutralization tower to detect the temperature of the alkali solution in the liquid alkali neutralization tower. If the temperature is too high, the alkali solution will evaporate easily. When the temperature is too high, the device will automatically stop running and automatically run again after natural cooling. If the temperature is too low, the alkali solution will freeze. If it is in an extremely cold area, the liquid alkali will freeze below a certain temperature. A liquid heater is installed in the neutralization tower, and a PLC is combined with a temperature sensor to heat the alkali solution to a certain temperature. The device fully considers the use in different geographical locations and has very strong applicability.

[0108] It is worth noting that as one of the improvements of the present invention over the prior art and one of the beneficial technical effects achieved, a mechanical stirring function is added to the alkali solution neutralization tower. When the pumped gas enters the alkali solution for neutralization, the alkali solution neutralization at the gas outlet position is easy to reduce the alkalinity. The alkali solution is continuously flowed through stirring. On the one hand, the alkaline substances are not precipitated in the solution. On the other hand, the alkali solution concentration maintained at the gas outlet position under the alkali solution due to the flow of the alkali solution can be maintained, thereby ensuring the neutralization ability.

[0109] Step 4: After the gas neutralized by the liquid alkali rises to the surface of the alkali solution, it flows through the molecular sieve adsorption bed to adsorb the fluoride and sulfide that were not adsorbed in the previous steps, so as to completely and cleanly adsorb all harmful substances. The molecular sieve has the ability to strongly and effectively adsorb these substances.

[0110] In a preferred but non-limiting embodiment of the present invention, the selected molecular sieve is an F series molecular sieve with strong adsorption of special acidic substances and a certain SF6 adsorption capacity. If there is any SF6 residue, it will be absorbed by the molecular sieve.

[0111] In a further preferred but non-limiting embodiment of the present invention, the molecular sieve adsorption bed adopts a layered filling structure of molecular sieve and solid calcium oxide. In addition to the effect of molecular sieve, solid calcium oxide is used as a secondary absorber to absorb the extremely small amount of acidic substances that are not neutralized in the alkali solution or the special substances that cannot be neutralized by the alkali solution, thereby achieving an ideal exhaust effect.

[0112] Step 5, sending the gas that has passed through the molecular sieve adsorption bed to the tail gas measurement chamber, monitoring the tail gas discharge according to the real-time online detection method, and sending the data to the computer system for comparison and display, judgment and control.

[0113] In a preferred but non-limiting embodiment of the present invention, the exhaust gas measurement chamber is equipped with a detector for detecting HF, SO2, H2S, SF4, the main substances produced after the decomposition of SF6, and residual SF6 that cannot be decomposed. The instrument measurement value is sent to the PLC controller and compared with the preset upper limit value. When the limit value is exceeded, an alarm of high content of a certain substance appears on the industrial control computer, and the machine automatically shuts down. At the same time, a prompt pops up: information such as catalyst failure, spray saturation, molecular sieve adsorption saturation, etc., to give a judgment on maintenance or replacement of parts.

[0114] In a preferred but non-limiting embodiment of the present invention, a second oil-free suction pump is used between the molecular adsorption bed and the tail gas measurement chamber. Specifically, since the mixed molecular sieve and calcium oxide have a certain density, a certain pressure difference is required for the gas to flow through. If there is no suction from this pump, the gas flow is not smooth, causing front-end blockage. The function of the second oil-free suction pump is to increase the inlet and outlet pressure difference of the molecular sieve adsorption bed through the suction force of the pump, so that the gas flows smoothly through the molecular sieve adsorption bed.

[0115] It is worth noting that one of the core concepts of the SF0 gas deep decomposition and adsorption device in a limited space provided by the present invention is to reduce energy consumption through the systematic design of the device. It can be understood by those skilled in the art that the special catalyst and adsorbent in the present invention refer to the catalyst and adsorbent specially used for SF6 gas catalytic adsorption in the prior art, and the technical effect of reducing energy consumption and reducing catalyst consumption can be obtained when using the special catalyst and adsorbent in the prior art. Obviously, those skilled in the art can also further develop special catalysts and adsorbents under the systematic design of the device of the present invention, replace the special catalysts and adsorbents in the prior art, and obtain the effect of reducing energy consumption and reducing the catalyst more optimized. These ways of implementing the present invention all fall within the scope of the core concept of the present invention.

[0116] It is worth noting that as one of the improvements of the present invention to the prior art and the beneficial technical effects achieved, the tail gas measurement chamber has built an environment for online real-time monitoring of data, and is a measurement flow pool with smooth circulation and close to atmospheric pressure. According to experimental detection, the main decomposition products of SF6 after thermal degradation are harmful substances such as hydrogen sulfide, sulfur dioxide, hydrogen fluoride, and sulfur tetrafluoride. By detecting these parameters, the control and judgment of whether the catalyst is invalid and whether the neutralization adsorption is invalid are controlled and judged. The data is transmitted remotely to the main control room, and the equipment automatically prompts the working status, effect, and whether the catalyst needs to be replaced, and whether solid alkali neutralization and liquid alkali neutralization need to add alkali or liquid. That is, the control system judges whether the catalyst is invalid based on the data.

[0117] It is worth noting that the present invention is significantly different from the prior art in at least the following aspects:

[0118] 1. The above process design is different from most of the current harmful gas thermal degradation treatment processes, which is most obvious in the special temperature of SF6 during thermal degradation and the multiplicity and complexity of decomposed substances after thermal degradation. An effective treatment process is designed through an easy-to-implement method, which is highly feasible, economical, environmentally friendly and safe.

[0119] 2. Different from some methods that require thermal degradation in a carrier gas environment, the inventors have developed a method that does not require any carrier gas, does not require the gas to be degraded to remove moisture and other components, and can be processed completely in a natural state. This has achieved the practicability and universal applicability of the device.

[0120] 3. The characteristics of temperature rise are effectively utilized, and a method of using temperature rise characteristics to reduce energy consumption is developed. Only a small amount of electricity is consumed to preheat the equipment when starting the equipment, which ensures the efficiency and effect of SF6 degradation and avoids the carbon emissions transferred by a large amount of electricity loss. It is extremely creative and innovative.

[0121] 4. After multiple neutralization treatments and adsorption, harmless emissions are achieved. For the working environment, the national standard has the "occupational exposure limit value for harmful factors in the workplace". The equipment fully complies with this standard, which not only solves the environmental protection problem, but also solves the occupational health protection problem.

[0122] 5. The device is equipped with multiple sensors, and the PLC automatically controls, judges and prompts whether the operating status of the device is good, which has strong applicability.

[0123] The beneficial effect of the present invention is that, compared with the prior art,

[0124] 1) This patented technical solution solves the problem that SF6 leaked and diffused into the atmosphere is difficult to recover and extract. The recovery and extraction of SF6 leaked and diffused into the atmosphere is very difficult and costly, and it cannot be stored. More importantly, it solves the serious greenhouse effect caused by the leakage and diffusion of SF6 in the atmosphere, and solves the problem that SF6 takes 3,000 to 5,000 years to be naturally degraded in the atmosphere.

[0125] 2) This patented technical solution solves the problem of large amounts of energy consumption required for incineration and degradation of SF6. The energy consumption required for heating and degradation of SF6 in this patented technical solution is extremely low. The device only needs to heat the catalytic adsorption tower to 600--800℃ and no longer needs electricity consumption. It only needs to consume extremely low electricity to maintain the operation of electrical control and oil-free suction pumps, and these components only consume 2-3kW of electricity. The device's electricity consumption is converted into carbon emissions for power generation, which is only equivalent to the energy consumption of a household cabinet air conditioner, which is far less than the energy consumption of uninterrupted industrial equipment. The operating cost is extremely low.

[0126] 3) The device consumes low amounts of catalysts. The device achieves a catalyst consumption ratio of SF6: catalyst = 1.2-1.5:1. The emission equivalent of 1kgSF6 is equivalent to 23,900kgCO2 (about 24 tons). The carbon emission cost is quite high. The cost of 1kg catalyst is less than RMB 80, which is equivalent to 1 / 24 of the carbon emission cost.

[0127] 4) After the device decomposes and adsorbs SF6, no secondary pollution or toxic substances are generated. The catalyst after decomposition and adsorption can be reused in construction, battery electrode material addition, and other metal alloy material additives. The exhaust gas emissions meet the occupational exposure limit standards for harmful factors in the workplace.

[0128] 5) The device is suitable for existing indoor and outdoor, underground substations, electrical manufacturing workshops, test halls of electrical testing institutes and other places where SF6 gas is used. The device is small in size, does not require installation, can be moved and placed, and enters working state as soon as it is turned on.

[0129] 6) The device has a high degree of automation, and all operating parameters and data can be monitored remotely.

[0130] The applicant of the present invention has made a detailed explanation and description of the implementation examples of the present invention in conjunction with the drawings in the specification. However, those skilled in the art should understand that the above implementation examples are only preferred implementation schemes of the present invention, and the detailed description is only to help readers better understand the spirit of the present invention, but not to limit the scope of protection of the present invention. On the contrary, any improvements or modifications based on the inventive spirit of the present invention should fall within the scope of protection of the present invention.

Claims

1. A device for deep decomposition and adsorption of SF6 gas in a limited space, comprising: A particle filter (1), a catalytic adsorption tower (2), a heat exchanger (3), a neutralization adsorption device, a first oil-free air suction pump (5), a molecular sieve adsorption bed (7), and a control system; characterized in that: The particle filter (1) is used to filter and inhale the atmosphere mixed with SF6, thereby blocking the dust particles and other substances in the environment; The catalytic adsorption tower (2) is connected to the particle filter (1) and is used to heat and decompose the SF6 mixed in the air sucked in the catalytic adsorption tower (2), and adsorb the decomposed product through a special adsorbent filled in the catalytic adsorption tower; the catalytic adsorption tower comprises: an air inlet, a pull rod (20), a barrel (30) and a material seat (40), and the outer side of the barrel (30) is an annular air supply channel (10); The heat exchanger (3) is connected to the catalytic adsorption tower (2), and the heat exchanger (3) cools down the high-temperature gas discharged from the catalytic adsorption tower (2); The neutralization adsorption device is connected to the heat exchanger (3) to neutralize the acidic substances that have not been completely adsorbed in the absorption catalytic adsorption tower (2); The first oil-free suction pump (5) is connected to the neutralization and adsorption equipment to provide power for the gas flow; The molecular sieve adsorption bed (7) is used to adsorb the residues that are not suitable for discharge before discharge; The control system is used to control the temperature of the catalytic adsorption tower (2), and utilizes the "temperature rise" of the catalytic adsorption tower (2) to control the temperature inside the catalytic adsorption tower (2) between a first set value and a second set value; the control system is also used to control and operate the interrelated parameters of various components of the decomposition adsorption device; The compressed air is connected to the control system, and when the compressed air is higher than a first set value, air supply to the catalytic adsorption tower barrel (30) for cooling is started; the control system dynamically controls the ventilation volume of the compressed air based on the temperature rise caused by the "flying temperature" on the catalytic adsorption tower.

2. The device for deep decomposition and adsorption of SF6 gas in a limited space according to claim 1, characterized in that: The neutralization and adsorption equipment comprises: a solid alkali neutralization tower (4) and a liquid alkali neutralization and adsorption tower (6); The solid alkali neutralization tower (4) is arranged between the heat exchanger (3) and the first oil-free suction pump (5) and is used to pre-neutralize in the solid alkali some decomposed acidic substances that have not been completely adsorbed after decomposition and adsorption; The liquid alkali neutralization adsorption tower (6) is arranged between the first oil-free air suction pump (5) and the molecular sieve adsorption bed (7) and is used to completely eliminate the acidic substances generated after SF6 is decomposed and adsorbed.

3. The device for deep decomposition and adsorption of SF6 gas in a limited space according to claim 2, characterized in that: The liquid alkali neutralization adsorption tower (6) is provided with a stirring device for improving the neutralization adsorption speed and effect.

4. The device for deep decomposition and adsorption of SF6 gas in a limited space according to claim 1, characterized in that: The SF6 gas deep decomposition and adsorption device in a limited space further comprises: a second oil-free air suction pump (8); The second oil-free air suction pump (8) is connected to the molecular sieve adsorption bed (7) and is used to provide power for the gas to flow in the molecular sieve adsorption bed (7).

5. The device for deep decomposition and adsorption of SF6 gas in a limited space according to claim 1, characterized in that: The SF6 gas deep decomposition and adsorption device in a limited space further comprises: an exhaust gas measurement chamber (9); The tail gas measurement chamber (9) is connected to the outlet end of the second air suction pump.

6. The device for deep decomposition and adsorption of SF6 gas in a limited space according to claim 5, characterized in that: The exhaust gas measurement chamber (9) is equipped with detectors for detecting HF, SO2, H2S, SF4, and residual SF6 that cannot be decomposed, which are generated after the decomposition of SF6. The measured values ​​of the instruments are sent to the control system.

7. The device for deep decomposition and adsorption of SF6 gas in a limited space according to claim 1, characterized in that: The SF6 gas deep decomposition and adsorption device in a limited space is a vehicle-mounted and movable equipment in a limited space. It can be moved with the vehicle to a scene where SF6 gas decomposition and adsorption is required, and can also be moved and placed in a limited space to a required working point.

8. A method for deep decomposition and adsorption of SF6 gas in a limited space, using the device for deep decomposition and adsorption of SF6 gas in a limited space as claimed in any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1, air containing SF6 enters the SF6 gas deep decomposition adsorption device in a limited space and is filtered at the particle filter (1); Step 2, the gas filtered in step 1 enters the catalytic adsorption tower (2), and the SF6 mixed in the air is thermally degraded in the catalytic decomposition tower. The "flying temperature" phenomenon of the catalytic adsorption tower (2) is utilized to maintain the temperature required for the catalytic adsorption tower (2) to continue working without adding any electric energy consumption, and the temperature in the catalytic adsorption tower (2) is controlled between the first set value and the second set value; Step 3, sending the gas flow with a higher temperature after passing through the catalytic adsorption tower process in step 2 to a heat exchanger, and then to a neutralization adsorption device to neutralize and absorb the acidic substances that have not been completely adsorbed in the catalytic adsorption tower (2); Step 4, continue to flow through the molecular sieve adsorption bed to adsorb the fluoride and sulfide that failed to be adsorbed in the previous steps, and adsorb all harmful substances; In step 5, the exhaust gas emission will be monitored by real-time online detection method, and the data will be sent to the control system for comparison and display, judgment and control.

9. The method for deep decomposition and adsorption of SF6 gas in a limited space according to claim 8, characterized in that: Step 1 comprises: using one or more SF6 content sensors in the environment; when no SF6 content is detected or the SF6 content is less than a set SF6 content value, the device is in a standby state; when the SF6 content is detected to reach a set value, the device automatically starts; entering a catalytic adsorption tower heating preparation state; when the catalytic adsorption tower reaches a catalytic temperature, the heat exchanger, the spray adsorption tower, the first oil-free air suction pump (5) and the second oil-free air suction pump (8) are automatically started in sequence.

10. A method for deep decomposition and adsorption of SF6 gas in a limited space according to claim 9, characterized in that: Step 3 includes: sending the high-temperature gas flow after passing through the catalytic adsorption tower process in step 2 into a heat exchanger to cool it to less than 100°C, and then entering a solid alkali neutralization tower to neutralize the acidic substances that have not been completely adsorbed after catalysis in the alkali neutralization tower, and sending the gas that has passed through the solid alkali neutralization tower to a liquid alkali neutralization adsorption tower.

11. A method for deep decomposition and adsorption of SF6 gas in a limited space according to claim 10, characterized in that: In step 3, the liquid alkali neutralization adsorption tower is a liquid alkali stirring neutralization tower, and the liquid alkali stirring neutralization tower is equipped with a pH sensor for real-time detection of the pH value of the alkali solution.

12. A method for deep decomposition and adsorption of SF6 gas in a limited space according to claim 11, characterized in that: In step 4, a second oil-free suction pump is used between the molecular adsorption bed and the tail gas measurement chamber to increase the inlet and outlet pressure difference of the molecular sieve adsorption bed through the suction force of the pump, so that the gas flows smoothly through the molecular sieve adsorption bed.

13. A method for deep decomposition and adsorption of SF6 gas in a limited space according to claim 12, characterized in that: In step 5, the exhaust gas measurement chamber is equipped with detectors for HF, SO2, H2S, SF4, the main substances produced after SF6 decomposition, and residual SF6 that cannot be decomposed. The instrument measurement value is sent to the PLC controller and compared with the preset upper limit value. When the limit value is exceeded, the industrial control computer will display an alarm of high content of a certain substance, and the machine will automatically shut down. At the same time, a prompt will pop up: catalyst failure, spray saturation, molecular sieve adsorption saturation related information, and a judgment will be made on maintenance or replacement of parts.

Images