Low-temperature plasma reaction system for eliminating leaked liquefied petroleum gas

Abstract

The invention belongs to the technical field of combustible gas leakage accident disposal, and particularly relates to a low-temperature plasma reaction system for eliminating leaked liquefied petroleum gas. The plasma reaction unit is used for eliminating leaked liquefied petroleum gas, and the plasma reaction unit comprises at least two stages of integrated double-dielectric barrier discharge plasma reactors which are connected in series / in parallel; at least two stages of air exhaust units, wherein each stage of air exhaust unit is correspondingly arranged at the air outlet of each stage of integrated double-dielectric barrier discharge plasma reactor; and the gas mixing unit is correspondingly arranged between the gas outlet of the previous stage of gas extraction unit and the gas inlet of the next stage of integrated double-dielectric barrier discharge plasma reactor. According to the invention, the liquefied petroleum gas is converted into a liquid product and a non-combustible gas based on a mode of converting gas through plasma reaction, so that the risk of combustible gas explosion is eliminated, the use safety level of LPG is improved, and the emergency disposal requirement of an LPG leakage accident site is better met.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of combustible gas leakage accident disposal, and particularly relates to a low-temperature plasma reaction system for eliminating leaked liquefied petroleum gas. BACKGROUND

[0002] Liquefied petroleum gas (LPG) is mainly derived from by-products produced in the crude oil refining process, as well as associated gas in the exploitation process of shale gas and natural gas, and is an important clean fuel and chemical raw material. The main components of LPG are propane and butane, and the explosion limit is 1.5% to 9.5%. Due to the relatively large density, low flash point and high heat value of LPG, after leakage, it is easy to gather and form a huge explosion safety hazard. Therefore, rapid elimination of leaked LPG can avoid or reduce the accident hazards and improve the safety level of LPG use.

[0003] At present, the disposal measures for LPG leakage accidents mainly include warning and evacuation, valve closing and source cutting, instrument plugging, water injection and risk removal, guide tank transfer, ignition of ignition point, and dilution and dispersion. These disposal measures standardize the whole process of LPG leakage accident disposal from the aspects of accident site warning and protection, personnel evacuation and rescue, leakage source control, and dilution and dispersion of leaked gas, and can effectively deal with LPG leakage accidents in most scenarios. The main measure for disposing the leaked LPG gas is dilution and dispersion, and the technical equipment is mainly spray water gun and smoke exhaust machine, that is, spray water or mechanical wind power is used to dilute and disperse the combustible gas in the environment, to prevent the undesirable gathering of LPG and reduce the LPG concentration in the accident site, so as to prevent explosion accidents. However, the measures of using spray water gun or smoke exhaust machine to dilute and disperse the leaked LPG gas, on the one hand, cannot eliminate the combustible gas, and even may cause the LPG gas to diffuse to the surrounding area, thereby forming a new danger source; on the other hand, in a limited space with poor ventilation, due to the relatively large relative density of LPG, the effectiveness of the dilution and dispersion disposal measure is poor, and it is often difficult to effectively dilute the LPG gas deposited at the bottom of the limited space. SUMMARY

[0004] In order to solve the above problems, the present application provides a low-temperature plasma reaction system for eliminating leaked liquefied petroleum gas. Based on the way of plasma reaction conversion gas, the present application extracts the leaked liquefied petroleum gas in the limited space, converts the leaked liquefied petroleum gas into liquid products and non-combustible gas through a double dielectric barrier discharge (DDBD) plasma reaction unit, thereby eliminating the explosion risk of combustible gas and improving the safety level of LPG use, to better meet the emergency disposal needs of LPG leakage accident site.

[0005] The present application solves the above technical problems through the following technical solutions.

[0006] The application aims to provide a low-temperature plasma reaction system for eliminating leaked liquefied petroleum gas, comprising: a plasma reaction unit for eliminating leaked liquefied petroleum gas, converting the liquefied petroleum gas into liquid products and non-combustible gas through low-temperature plasma reaction, the plasma reaction unit comprising at least two-stage integrated double dielectric barrier discharge plasma reactors in series / parallel connection; at least two-stage gas suction units, each gas suction unit being arranged at the gas outlet of the corresponding integrated double dielectric barrier discharge plasma reactor, the gas suction unit being used for sucking the leaked liquefied petroleum gas into the integrated double dielectric barrier discharge plasma reactor; a gas mixing unit arranged between the gas outlet of the upper-stage gas suction unit and the gas inlet of the lower-stage integrated double dielectric barrier discharge plasma reactor, the gas mixing unit being used for mixing air and the leaked liquefied petroleum gas which is not completely reacted and conveying the mixed gas to the lower-stage integrated double dielectric barrier discharge plasma reactor.

[0007] Further, all the integrated double dielectric barrier discharge plasma reactors are electrically connected to a plasma power source, the plasma power source being used for providing discharge for the integrated double dielectric barrier discharge plasma reactors, each integrated double dielectric barrier discharge plasma reactor comprising a plurality of single double dielectric barrier discharge plasma reactors and a shell.

[0008] Further, the single double dielectric barrier discharge plasma reactor comprises an inner barrier dielectric tube, an outer barrier dielectric tube, a high-voltage pole and a grounded electrode net, the outer wall of the outer barrier dielectric tube is coaxial with the inner barrier dielectric tube, a ring-cylinder plasma discharge gap is arranged between the outer barrier dielectric tube and the inner barrier dielectric tube, a reaction gas inlet and a reaction gas outlet are arranged at two ends of the ring-cylinder plasma discharge gap respectively, the liquefied petroleum gas passes through the plasma discharge gap to occur conversion reaction, the high-voltage pole is arranged inside the inner barrier dielectric tube, the outer wall of the outer barrier dielectric tube is provided with the grounded electrode net, and one end of the high-voltage pole is electrically connected to the plasma power source.

[0009] Further, the integrated double dielectric barrier discharge plasma reactor is provided with a reactor shell, the inner barrier dielectric tube, the outer barrier dielectric tube and the high-voltage pole are all insulated and sealedly connected to the inner wall of the reactor shell, and the reaction gas inlet and the plasma discharge gap are communicated.

[0010] Further, each integrated double dielectric barrier discharge plasma reactor is provided with one first gas inlet and one first gas outlet; all the first gas inlets are connected with first anti-static gas suction hoses.

[0011] Further, the first anti-static gas suction hoses are all provided with first valves, and the gas inlets of the first anti-static gas suction hoses are all provided with filters.

[0012] Further, all the first gas outlets are connected with a second anti-static air exhaust hose, each second anti-static air exhaust hose is connected with the air inlet of the air exhaust unit one by one, and a condenser is arranged on each second anti-static air exhaust hose to condense liquid products.

[0013] Further, the air exhaust unit is provided with a second gas outlet and a third gas outlet, the second gas outlet is connected with the air inlet of the air mixing unit through a third anti-static air exhaust hose, a second valve is arranged on the third anti-static air exhaust hose, and the third gas outlet is provided with a third valve.

[0014] Further, the air mixing unit comprises an air mixing chamber and a blower, the air inlet of the air mixing chamber is connected with the second gas outlet of the upper-stage integrated double dielectric barrier discharge plasma reactor through the third anti-static air exhaust hose, the air outlet of the air mixing chamber is connected with the first air inlet of the lower-stage integrated double dielectric barrier discharge plasma reactor through the third anti-static air exhaust hose, and the air outlet of the blower is connected with the air inlet of the air mixing chamber.

[0015] Compared with the prior art, the application has the following beneficial effects: (3) Based on the mode of converting gas through plasma reaction, the application carries out low-temperature plasma reaction through at least two stages of integrated double dielectric barrier discharge plasma reactors in series / parallel connection, converts liquefied petroleum gas into liquid products and non-combustible gas, controls the flow of reaction gas by using the air exhaust unit, mixes air and unreacted liquefied petroleum gas by using the air mixing unit if the concentration of LPG is too high (more than 5%), and carries out low-temperature plasma reaction through the second-stage integrated double dielectric barrier discharge plasma reactor in series connection, so as to convert liquefied petroleum gas into liquid products and non-combustible gas, thereby eliminating the risk of explosion of combustible gas and improving the safety level of LPG use.

[0016] (4) The double dielectric barrier discharge plasma reactor provided by the application carries out chemical reaction in the form of free radicals, positive and negative ions and excited-state atoms through high-energy electron non-elastic collision to cause dissociation and excitation of gas molecules under mild conditions of normal temperature and pressure, partially oxidizes the leaked LPG into liquid oxygen-containing compounds such as alcohols, aldehydes and ketones by using O2 and H2O naturally existing in air, thereby eliminating the risk of explosion of LPG gas, and the application does not need to use decontamination agents and adsorbents, is an efficient and controllable explosion elimination technology, and has the advantages of rapid response, simple equipment and flexible movement. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 It is a structure schematic view of a low-temperature plasma reaction system for eliminating leaked liquefied petroleum gas.

[0018] Figure 2Structure diagram of monomer double dielectric barrier discharge plasma reactor of the present application.

[0019] Figure 3 Structure diagram of simulation system for eliminating leakage liquefied petroleum gas of the present application.

[0020] Figure 4 C4H 10 Concentration of C4H 10 and CO in exhaust gas under initial concentration of 5% C4H

[0021] Figure 5 C4H 10 Concentration of C4H 10 and CO under initial concentration of 15% C4H Figure 5 C4H 10 Concentration of C4H

[0022] Figure 6 C4H 10 Concentration of C4H 10 and CO in exhaust gas under initial concentration of 25% C4H

[0023] Figure 7 C4H 10 Concentration of C4H 10 and CO under initial concentration of 25% C4H Figure 7 C4H 10 Concentration of C4H

[0024] Figure 8 C4H 10 Concentration of C4H 10 and CO in exhaust gas under initial concentration of 25% C4H

[0025] Figure 9 C4H 10 Concentration of C4H 10 and CO under initial concentration of 25% C4H Figure 9 C4H 10 Concentration of C4H DETAILED DESCRIPTION

[0026] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application.

[0027] It should be noted that the professional terms used in the present application are only for the purpose of describing the specific embodiments, and are not intended to limit the protection scope of the present application. In the present application, certain terms are used to refer to specific components. Those skilled in the art should understand that the same component can be referred to by different terms. The present application does not distinguish components by the difference in terms, but by the difference in function. As mentioned throughout the specification and claims, "including" is an open term, so it should be understood as "including but not limited to".

[0028] The present application provides a low-temperature plasma reaction system for eliminating leaked liquefied petroleum gas, comprising: The plasma reaction unit is used for eliminating leaked liquefied petroleum gas, and converts the liquefied petroleum gas into liquid products and non-combustible gas through low-temperature plasma reaction. The plasma reaction unit comprises at least two stages of integrated double dielectric barrier discharge plasma reactors 1 in series / parallel connection; at least two stages of gas extraction units 2, each of which is arranged at the gas outlet of the two-stage integrated double dielectric barrier discharge plasma reactor 1, and is used for sucking the leaked liquefied petroleum gas to be eliminated into the integrated double dielectric barrier discharge plasma reactor 1; and a gas mixing unit 3 arranged between the gas outlet of the upper-stage gas extraction unit and the gas inlet of the lower-stage integrated double dielectric barrier discharge plasma reactor 1, and used for mixing air and the leaked liquefied petroleum gas which is not completely reacted and then conveying them to the lower-stage integrated double dielectric barrier discharge plasma reactor 1.

[0029] In the present application, the plasma reaction unit generates low-temperature plasma under certain discharge conditions to make the mixed gas of LPG, air and water vapor undergo plasma conversion reaction. In a preferred embodiment, the plasma reaction unit can be a two-stage integrated double dielectric barrier discharge plasma (DDBD) reactor 1 to eliminate the leaked liquefied petroleum gas (LPG), and an air extraction unit is used to control the flow of reaction gas. When the LPG concentration is low (e.g. less than 5%), the two-stage integrated double dielectric barrier discharge plasma reactor 1 includes a first-stage integrated DDBD reactor and a second-stage integrated DDBD reactor, and the two-stage air extraction unit 2 includes a first-stage air extraction unit and a second-stage air extraction unit. The first-stage air extraction unit and the second-stage air extraction unit respectively suck the leaked LPG into the first-stage integrated double dielectric barrier discharge plasma reactor 1 and the second-stage integrated double dielectric barrier discharge plasma reactor 1. The gas mixing unit is closed, and the two-stage integrated double dielectric barrier discharge plasma reactor 1 is started simultaneously to eliminate low-concentration LPG, which is completely converted into liquid products and non-combustible gas, thereby eliminating the risk of combustible gas explosion and improving the safety level of LPG use. The plasma reaction unit can also be a two-stage integrated double dielectric barrier discharge plasma reactor 1 to eliminate the leaked LPG, and an air extraction unit is used to control the flow of reaction gas. In a preferred embodiment, when the LPG concentration is too high (e.g. more than 5%), the high-concentration LPG is first eliminated by the first-stage integrated DDBD reactor. If it cannot completely convert the high-concentration LPG into liquid products and non-combustible gas, the air mixing unit is used to mix the air and the unreacted LPG, and then the second-stage integrated DDBD reactor is used for low-temperature plasma reaction to completely convert the LPG into liquid products and non-combustible gas, thereby eliminating the risk of combustible gas explosion and improving the safety level of LPG use. The DDBD reactor can generate high-energy electrons to undergo dissociative excitation reaction. The high-energy electrons first dissociate the C-C, C-H, O=O and N≡N bonds in the LPG, O2 and N2 molecules through non-elastic collision to generate active species such as free radicals, and then undergo partial oxidation reaction through free radical reaction pathway. The intermediate products are mainly generated by high-carbon or oxygen-containing liquid products through mutual combination, and part of them are oxidized to gaseous product CO x .

[0030] In some embodiments, all integrated double dielectric barrier discharge plasma reactors 1 are electrically connected to a plasma power supply for providing discharge for the integrated double dielectric barrier discharge plasma reactors 1, each of which comprises a plurality of single double dielectric barrier discharge plasma reactors 1-1 and a housing. The housing is made of explosion-proof material. In the present application, the plasma power supply used is a high-voltage modulated pulse plasma power supply, which is a high-voltage power supply form combining a sinusoidal waveform and a pulse waveform. A low-frequency rectangular pulse signal (pulse frequency) is used to modulate a high-frequency sinusoidal wave signal (excitation frequency), thereby obtaining a sinusoidal wave discharge with modulated pulse characteristics. In a specific embodiment, each integrated double dielectric barrier discharge plasma reactor 1 comprises 1000 single DDBD reactors, each of which is designed to be 30 cm long and 1 cm in outer diameter. The single DDBD reactors can also be filled with catalysts, which can be MnO x -Al2O3 catalysts. Considering the gaps between the single DDBD reactors and the gas inlet and outlet flow spaces, each integrated DDBD reactor is a cube with a length of 90 cm and a width and height of 110 cm, and a volume of about 1.1 m 3

[0031] In some embodiments, the single double dielectric barrier discharge plasma reactor 1-1 comprises an inner barrier medium tube 1-2, an outer barrier medium tube 1-3, a high-voltage pole 1-4, and a grounded electrode mesh 1-5. The inner barrier medium tube 1-2 is provided with a coaxial outer barrier medium tube 1-3. A ring-cylinder-shaped plasma discharge gap is provided between the outer barrier medium tube 1-3 and the inner barrier medium tube 1-2. A gas inlet and a gas outlet are respectively located at the two ends of the ring-cylinder-shaped plasma discharge gap. The inner barrier medium tube 1-2 is provided with a high-voltage pole 1-4. The outer wall of the outer barrier medium tube 1-3 is provided with a grounded electrode mesh 1-5. One end of the high-voltage pole 1-4 is electrically connected to the plasma power supply.

[0032] In some embodiments, the integrated double dielectric barrier discharge plasma reactor 1 is provided with a reactor housing 1-8. The inner barrier medium tube 1-2, the outer barrier medium tube 1-3, and the high-voltage pole 1-4 are all insulated and sealedly connected to the inner wall of the reactor housing 1-8. The reaction gas inlet 1-6 and the plasma discharge gap are sealedly communicated. The inner barrier medium tube 1-2, the outer barrier medium tube 1-3, the high-voltage pole 1-4, and the grounded electrode mesh 1-5 are all arranged in the housing. The reactor housing 1-8 is used to protect and fix the DDBD plasma reactor.

[0033] ​In the present application, the inner wall of the shell is also provided with a heat dissipation window and an observation window. The inner barrier medium tube 1-2 and the outer barrier medium tube 1-3 are both quartz tubes, the inner barrier medium tube 1-2 is a quartz tube with an outer diameter of 16 mm and an inner diameter of 12 mm, the inner barrier medium tube 1-2 is internally provided with a high-voltage electrode 1-4, the high-voltage electrode 1-4 is a stainless steel rod with a diameter of 4 mm, and the gap between the inner barrier medium tube 1-2 and the high-voltage electrode 1-4 is filled with aluminum powder. The outer barrier medium tube 1-3 is a quartz tube with an outer diameter of 25 mm and an inner diameter of 20 mm, and a grounding electrode mesh 1-5 is arranged on the outer wall of the outer barrier medium tube 1-3, the grounding electrode mesh 1-5 is a stainless steel mesh with a width of 120 mm. The two ends of the inner barrier medium tube 1-2, the outer barrier medium tube 1-3 and the high-voltage electrode 1-4 are connected through the inner wall of the shell and the sealing gasket, and the grounding electrode mesh 1-5 is also provided with a grounding end. In the gap between the outer barrier medium and the inner barrier medium, a cylindrical plasma discharge region with a discharge width of 120 mm, a discharge gap of 2 mm and a discharge volume of about 13.56 mL is formed.

[0034] In some embodiments, each integrated dual dielectric barrier discharge plasma reactor 1 is provided with a first gas inlet and a first gas outlet; all first gas inlets are connected with first anti-static air exhaust hoses 4.

[0035] In some embodiments, the first anti-static air exhaust hoses 4 are each provided with a first valve, and the gas inlets of the first anti-static air exhaust hoses 4 are each provided with a filter. The flow of leaked LPG into each integrated dual dielectric barrier discharge plasma reactor 1 can be controlled through the first valve and the air exhaust unit, the first anti-static air exhaust hoses 4 extend into the limited space where LPG leaks, and the leaked LPG is sucked through the air exhaust unit. The filter functions to suck the leaked LPG and prevent other solid impurities from entering the DDBD reactor.

[0036] In some embodiments, all first gas outlets are connected with a second anti-static air exhaust hose 6, each second anti-static air exhaust hose 6 is connected with an air inlet of the air exhaust unit one by one, and each second anti-static air exhaust hose 6 is provided with a condenser. The condenser is used to condense the products output from the second anti-static air exhaust hose 6, so that the low-boiling-point products in the products are condensed into liquid, preventing liquid products from entering and clogging the air exhaust unit.

[0037] In some embodiments, the two-stage air exhaust unit 2 is provided with a second gas outlet and a third gas outlet, the second gas outlet and the air inlet of the gas mixing unit are connected through a third anti-static air exhaust hose 7, the third anti-static air exhaust hose 7 is provided with a second valve, and the third gas outlet is provided with a third valve. The air exhaust unit is an air exhaust machine, and the suction flow of the air exhaust machine is not less than 105 m 3 / h, thereby controlling the flow of leaked LPG into the first anti-static air extraction hose 4 to make the LPG washing and eliminating device body work in a safe area. When each integrated DDBD reactor reacts completely with the leaked LPG, it is discharged through the third air outlet. When the first-stage integrated DDBD reactor does not completely eliminate the leaked LPG, the third valve on the first air extraction unit connected thereto can be closed, and the incompletely eliminated leaked LPG is transported to the gas mixing unit through the third anti-static air extraction hose 7, and the gas mixing unit mixes the incompletely reacted leaked LPG, the newly generated gas, and the air sent by the air blower 10, and continues to react through the second-stage integrated DDBD reactor.

[0038] In some embodiments, the gas mixing unit 3 comprises a gas mixing chamber 9 and an air blower 10. The gas mixing chamber 9 is connected to the second air outlet of the first-stage integrated dual dielectric barrier discharge plasma reactor 1 through the third anti-static air extraction hose 7, and the gas mixing chamber 9 is connected to the first air inlet of the second-stage integrated dual dielectric barrier discharge plasma reactor 1 through the third anti-static air extraction hose 7. The air outlet of the air blower 10 is connected to the air inlet of the gas mixing chamber 9. The air blower 10 is used to transport air into the gas mixing chamber 9, and mix the incompletely reacted leaked LPG, the newly generated gas, and the air sent by the air blower 10, and transport them to the second-stage integrated dual dielectric barrier discharge plasma reactor for reaction.

[0039] The following is further illustrated by specific embodiments.

[0040] Embodiments This embodiment provides a method for eliminating the explosion risk of leaked LPG by using an analog system to prove the feasibility of the low-temperature plasma reaction system for eliminating leaked LPG.

[0041] The simulation system comprises the above-mentioned low-temperature plasma reaction system for eliminating leaked LPG, the plasma reaction unit is only a single DDBD reactor 1-1, and butane is used to replace the leaked LPG for testing. The suction device is replaced by a gas distribution unit for simulating the elimination of the leaked LPG. The gas distribution unit comprises an air supply compressed gas cylinder 3-1, a butane gas cylinder 3-2, a bubbling chamber 3-3, and a gas mixing chamber 3-4. The outlet of the air supply compressed gas cylinder 3-1 is connected to the inlet of the bubbling chamber 3-3 through a first gas guide pipe, the outlet of the bubbling chamber 3-3 is connected to the inlet of the gas mixing chamber 3-4 through a second gas guide pipe, and the outlet of the gas mixing chamber 3-4 is connected to the gas inlet of the single DDBD reactor 1-1 through a third gas guide pipe. A gas mass flow controller is arranged on the first gas guide pipe. The outer wall of the bubbling chamber 3-3 and the gas mixing chamber 3-4 is provided with a heating thermostat 3-5, and water is arranged in the bubbling chamber 3-3 for providing water vapor. The butane gas cylinder 3-2 is connected to the inlet of the gas mixing chamber 3-4 through a gas guide pipe for providing butane. A gas mass flow controller is arranged on the gas guide pipe. In this embodiment, the proportioning and flow of the mixed gas in the gas mixing chamber 3-4 are controlled by the gas mass flow controllers. The outer wall of the bubbling chamber 3-3 and the gas mixing chamber 3-4 is provided with a heating thermostat 3-5, and water is arranged in the bubbling chamber 3-3. When the air enters the bubbling chamber 3-3 from the water, the air containing water vapor is formed. By controlling the temperature of the heating thermostat, the water vapor content is controlled to simulate the water vapor content in the air under different environments. The air containing water vapor is mixed with butane in the gas mixing chamber 3-4 to simulate the leaked LPG, and finally enters the DDBD reactor. A heat tracing belt is arranged outside the gas guide pipe between the outlet of the gas mixing chamber 3-4 and the gas inlet of the DDBD reactor to ensure that the water vapor in the gas pipeline does not condense.

[0042] The single DDBD reactor 1-1 and the plasma power supply 3-6 are further connected to an oscilloscope 3-7. In the embodiment, the oscilloscope 3-7 collects the voltage and current signals of the plasma reactor 3-6, respectively. The model of the oscilloscope 3-7 is MDO34. The electrical signals are recorded and stored, and the discharge parameters of the DDBD reactor are calculated.

[0043] A product collection unit and a detection and analysis unit are arranged at the gas outlet of the DDBD reactor.

[0044] The product collection unit includes a product collector 3-8 and a condenser 3-9. The product collector 3-8 is connected to the gas outlet, and is further provided with a gas flow meter 3-10 and a temperature and humidity detector. The condenser 3-9 is connected to the product collector and is used to condense and collect liquid products. In this embodiment, the condenser 3-9 is used to condense the products output from the gas outlet, so that the low-boiling-point products in the products are condensed into liquid. At the same time, the gas flow of the gaseous products and the temperature of the gaseous products are detected by the gas flow meter 3-10 and the temperature and humidity detector, respectively. The product collector 3-8 is connected to the detection and analysis unit and transports the liquid products and gaseous products to the detection and analysis unit, respectively. The product collector 3-8 is further provided with a gas storage device and the condenser 3-9, which are used to collect and store gaseous products and liquid products. After the gaseous products and liquid products are collected and stored sufficiently, the gaseous products are extracted for detection. The gas flow meter 3-10 is a soap film flow meter.

[0045] The detection and analysis unit includes a gas chromatograph-mass spectrometer 3-11 and a flue gas analyzer 3-12. Both the gas chromatograph-mass spectrometer 3-11 and the flue gas analyzer are connected to the product collector. The gas chromatograph-mass spectrometer 3-11 is used to qualitatively and quantitatively analyze the unconverted butane, gaseous products and liquid products. The flue gas analyzer 3-12 is used to detect and analyze the oxygen concentration and carbon monoxide concentration in the gaseous products, determine the conversion rate of the leaked butane, and select the main gaseous and liquid products. In this embodiment, the gas chromatograph-mass spectrometer 3-11 is further provided with different chromatographic columns. The GS-GasPro 113-4362 chromatographic column is used to qualitatively and quantitatively analyze the unconverted butane, gaseous products other than oxygen and carbon monoxide gas, such as CO2, methane, ethane, ethylene, propane, propylene and 2-butene, etc. The DB-624 122-1334U chromatographic column is used to qualitatively and quantitatively analyze the liquid products. The flue gas analyzer 3-12 is used to detect and analyze the oxygen concentration and carbon monoxide concentration in the gaseous products.

[0046] Specifically, the following steps are included: Step 1: Turn on the flue gas analyzer and use the ambient air to calibrate. Turn on the oscilloscope, connect the passive voltage probe interface, and check to ensure stable signal transmission. Install the internal electrode of the DDBD reactor.

[0047] Step 2, check and connect the high-voltage modulation pulse power supply, make sure the ground wire is well grounded, check the gas pipeline of the gas cylinder, gas mass flow controller, gas mixing chamber, DDBD reactor, etc. to ensure that the pipeline connection is good and there is no gas pipeline leakage phenomenon. Connect the DDBD reactor outlet to the product collector, insert the temperature and humidity recorder in the product collector, connect the gaseous product exhaust pipe to the detection and analysis unit. Open the cooling water circulation system of the condenser. Open the compressed air cylinder and butane supply compressed gas cylinder, adjust the outlet pressure to about 0.1 MPa. Open the gas mass flow controller, adjust the butane and air flow to the predetermined flow rate, and record the gas temperature after the gas flow is stable. Measure the gas flow with a soap film flowmeter to calibrate the gas flow.

[0048] Step 3, connect and turn on the high-voltage modulation pulse power supply, set the pulse frequency and duty cycle, adjust the applied voltage to the predetermined voltage. Wait for 20 min, at this time the initial concentration of butane in the gas pipeline is basically stable at the preset concentration, and the temperature of the DDBD reactor is also basically stable, the system preheating is completed. The power of the pulse discharge is set to 22 W-65 W, the flow rate of the mixed gas is 0.22 L / min-1.32 L / min, the volume concentration of butane in the mixed gas is 5%-25%, and the volume concentration of water vapor is 0%-8%.

[0049] Step 4, measure the tail gas flow using a soap film flowmeter, and record the gaseous product temperature. Insert a U disk into a digital oscilloscope, use the digital oscilloscope to collect discharge signals, first adjust the oscilloscope screen display to contain 7 complete pulse periods (modulation periods), save the waveform data of 7 complete pulse periods; then adjust the oscilloscope screen display to contain 1 complete sine wave (carrier wave) period, save the 1 sine wave data whose voltage peak reaches the preset peak voltage, then export the data with the U disk. First, use the gas storage device to collect gaseous products for gas detection using a gas chromatograph mass spectrometer. Then use the gas storage device to collect gaseous products, and after the gas is collected sufficiently, use a flue gas analyzer to extract gaseous products from the gas storage device for detection. The temperature measuring gun detects the temperature of the stainless steel mesh of the DDBD reactor at a fixed position. After the system is stable for 1 h, the applied voltage is returned to zero and the high-voltage modulation pulse power supply is turned off, the compressed air cylinder and the butane cylinder are turned off, the gas mass flow controller is turned off, and the liquid product in the liquid collector is collected into a sample bottle and weighed.

[0050] Step 5, first use a gas chromatograph mass spectrometer to qualitatively analyze the gaseous and liquid products to determine the main components; then configure standard samples and draw standard curves, and finally quantitatively analyze the gaseous and liquid products to determine the conversion rate of butane after leakage, and the selectivity of the main gaseous and liquid products.

[0051] Figure 45% C4H 10 initial concentration in the tail gas 10 and CO concentration with NTP energy density and fitting curve. As shown in Figure 4 , when the energy density tends to 0 kJ / L, the C4H 10 concentration in the tail gas should tend to C4H 10 initial concentration, with the continuous increase of energy density, the C4H 10 concentration in the tail gas should tend to 0%, so it is considered that the C4H 10 concentration in the tail gas decreases exponentially with the increase of NTP energy density ED , the fitting result is good; when the energy density tends to 0.00 kJ / L, the CO concentration in the tail gas should tend to 0%, and then the CO concentration increases first and then decreases with the increase of energy density, and the increasing and decreasing rates both have the trend of first increasing and then decreasing, and finally the CO concentration in the tail gas tends to 0% with the continuous increase of energy density, so it is considered that the CO concentration in the tail gas may have a cubic relationship with NTP energy density ED , the fitting result is good. Through calculation, when the energy density ED ≥2.17 kJ / L, the C4H 10 concentration C C4H10 in the tail gas is ≤1.9%, and the CO concentration C CO in the tail gas is ≥0.83%; when ED ≤1.42 kJ / L, the CO concentration C CO in the tail gas is ≤0.4%, and the C4H 10 concentration C C4H10 in the tail gas is ≥2.5%.

[0052] Figure 5 5% C4H 10 initial concentration under the change of gas flow and discharge power, the relationship between C4H 10 and CO concentration and energy density, Figure 5 (a) is the C4H 10 concentration, and (b) is the CO concentration. As shown in Figure 5 , by changing the gas flow under the fixed low discharge power (22 W), it is found that at the same energy density, the C4H 10 and CO concentration in the tail gas are relatively low. And by changing the discharge power (higher discharge power) under the fixed gas flow (1.32 L / min and 0.66 L / min), it is found that at the same energy density, the C4H 10 and CO concentration in the tail gas are relatively high. Therefore, it is concluded that in order to obtain the best decontamination effect, the discharge power should be fixed at a lower value, and the gas flow should be adjusted to implement C4H10 Decontamination. Additionally, if it is necessary to accelerate C4H... 10 The overall removal rate should be increased by connecting more DDBD reactors in parallel to increase the total gas flow rate, thereby rapidly implementing C4H. 10 Disinfection.

[0053] Figure 6 The present invention contains 15% C4H 10 C4H in exhaust gas at initial concentration 10 The variation of CO concentration with NTP energy density and the fitted curve. Figure 6 As shown, 15% C4H 10 C4H in exhaust gas at initial concentration 10 The relationship between NTP energy density and CO concentration and 5% C4H 10 The patterns are similar at initial concentrations. The curve obtained by fitting the CO concentration data with a cubic function shows good fitting results, especially at energy densities. ED When the concentration of C4H10 in the exhaust gas is ≥14.49 kJ / L, C C4H10 ≤1.9%, while CO concentration C CO ≥9.15%; when ED ≤2.17kJ / L, CO concentration C in exhaust gas CO ≤0.40%, while C4H 10 Concentration C C4H10 ≤10.9%.

[0054] Figure 7 The present invention contains 15% C4H 10 When the initial concentration changes the gas flow rate and discharge power, C4H 10 The relationship between CO concentration and energy density, Figure 7 In the middle (a), C4H 10 Concentration, (b) is the CO concentration. For example... Figure 7 As shown, by changing the gas flow rate while maintaining a fixed low discharge power (22W), a lower C4H content was obtained at the same energy density. 10 When the CO concentration is significantly lower than that at a fixed, larger gas flow rate (1.32 L / min and 0.66 L / min), the C4H obtained by changing the discharge power (higher discharge power) is significantly lower. 10 and CO concentration. Therefore, in order to obtain the best C4H 10 For effective decontamination, the discharge power should be kept constant at a relatively low level, and the C4H emission rate should be adjusted by regulating the gas flow rate. 10 Decontamination. Additionally, if it is necessary to accelerate C4H... 10 The overall removal rate should be increased by connecting more DDBD reactors in parallel to increase the total gas flow rate, thereby enabling rapid implementation of C4H.10 While disinfecting, a lower C4H level is achieved. 10 and CO concentration.

[0055] Figure 8 The present invention contains 25% C4H 10 C4H in exhaust gas at initial concentration 10 The graph shows the variation of CO concentration with NTP energy density. Figure 8 As shown, 25% C4H 10 C4H in exhaust gas at initial concentration 10 The relationship between CO concentration and energy density changes with 5% and 15% C C4H10 The patterns are similar at initial concentrations. For C... C4H10 The curve obtained after fitting the concentration data showed good fitting results. Calculations showed that when the energy density... ED When reaching a maximum of 17.7 kJ / L, the C4H in the exhaust gas 10 Concentration C C4H10 Still as high as 9.2%; when ED ≤3.24 kJ / L, CO concentration C in exhaust gas CO ≤0.40%.

[0056] Figure 9 The present invention contains 25% C4H 10 C4H at initial concentration, changing gas flow rate and discharge power 10 The relationship between CO concentration and energy density, Figure 9 In the middle (a), C4H 10 Concentration, (b) is the CO concentration. For example... Figure 9 As shown, by changing the gas flow rate while keeping the low discharge power (22 W) constant, the exhaust gas at the same energy density achieved a lower C4H content. 10 When the CO concentration is significantly lower than the constant gas flow rate (1.32 L / min and 0.66 L / min), the C4H in the exhaust gas obtained by changing the discharge power (higher discharge power) is... 10 And CO concentration. Therefore, it is concluded that, to obtain the best decontamination effect, the discharge power should be kept constant at a low level, and C4H should be implemented by adjusting the gas flow rate. 10 Decontamination. If faster C4H is required... 10 The overall decontamination rate should be increased by connecting more DDBD reactors in parallel to increase the total gas flow rate, thereby achieving rapid decontamination of C4H. 10 At the same time, achieve lower C4H 10 and CO concentration.

[0057] To sum up, the application uses the air distribution unit to form mixed gas by air, LPG and water vapor to simulate the leaked LPG, carries out experimental test through the DDBD plasma reactor, obtains the influence of discharge power, gas flow (reaction time), butane initial concentration and water vapor content on the low-temperature plasma reaction, safely eliminates the explosion risk of butane mixed gas, and proves the feasibility of the low-temperature plasma reaction system for eliminating the leaked LPG.

[0058] It should be noted that when the numerical range is involved in the application, it should be understood that each numerical range can be selected from two endpoints and any number between the two endpoints, and since the same step method and example are adopted, the preferred examples are described in the application to prevent redundancy. Although the preferred examples of the application have been described, those skilled in the art can make additional changes and modifications to the examples once they know the basic creative concept. Therefore, the appended claims are intended to include the preferred examples and all changes and modifications falling within the scope of the application.

[0059] Obviously, those skilled in the art can make various modifications and variations to the application without departing from the spirit and scope of the application. Thus, if these modifications and variations of the application belong to the scope of the claims of the application and their equivalent technologies, the application also intends to include these modifications and variations.

Claims

1. A cryogenic plasma reaction system for eliminating leaking liquefied petroleum gas, characterized by, The application relates to a device for eliminating leaked liquefied petroleum gas, comprising: a plasma reaction unit for eliminating leaked liquefied petroleum gas, converting the liquefied petroleum gas into liquid products and non-combustible gas through low-temperature plasma reaction, the plasma reaction unit comprising at least two-stage integrated double dielectric barrier discharge plasma reactors (1) in series / parallel connection; at least two-stage gas suction units (2), each gas suction unit being arranged at the gas outlet of each-stage integrated double dielectric barrier discharge plasma reactor (1), the gas suction unit (2) being used for sucking the leaked liquefied petroleum gas into the integrated double dielectric barrier discharge plasma reactor (1); and a gas mixing unit (3) arranged between the gas outlet of the upper-stage gas suction unit and the gas inlet of the lower-stage integrated double dielectric barrier discharge plasma reactor (1), the gas mixing unit (3) being used for mixing air and the leaked liquefied petroleum gas which is not completely reacted and conveying the mixture to the lower-stage integrated double dielectric barrier discharge plasma reactor (1). All the integrated double dielectric barrier discharge plasma reactors (1) are electrically connected with a plasma power supply, the plasma power supply being used for providing discharge for the integrated double dielectric barrier discharge plasma reactors (1), each integrated double dielectric barrier discharge plasma reactor (1) comprising a plurality of single double dielectric barrier discharge plasma reactors (1-1) and a shell. The single double dielectric barrier discharge plasma reactor (1-1) comprises an inner barrier medium tube (1-2), an outer barrier medium tube (1-3), a high-voltage pole (1-4) and a grounded electrode net (1-5), the outer barrier medium tube (1-3) is coaxially arranged outside the inner barrier medium tube (1-2), a ring-cylinder plasma discharge gap is arranged between the outer barrier medium tube (1-3) and the inner barrier medium tube (1-2), the two ends of the ring-cylinder plasma discharge gap are respectively provided with a reaction gas inlet (1-6) and a reaction gas outlet (1-7), the liquefied petroleum gas passes through the plasma discharge gap to generate a conversion reaction, the high-voltage pole (1-4) is arranged inside the inner barrier medium tube (1-2), the outer wall of the outer barrier medium tube (1-3) is provided with the grounded electrode net (1-5), and one end of the high-voltage pole (1-4) is electrically connected with the plasma power supply. The integrated double dielectric barrier discharge plasma reactor (1) is provided with a reactor shell (1-8), the inner barrier medium tube (1-2), the outer barrier medium tube (1-3) and the high-voltage pole (1-4) are all in insulating and sealing connection with the inner wall of the reactor shell (1-8), and the reaction gas inlet (1-6) is in communication with the plasma discharge gap.

2. The low temperature plasma reaction system for eliminating leaked liquefied petroleum gas according to claim 1, wherein Each integrated double dielectric barrier discharge plasma reactor (1) is provided with one first gas inlet and one first gas outlet; all the first gas inlets are connected with first anti-static gas suction hoses (4).

3. The low temperature plasma reaction system for eliminating leaked liquefied petroleum gas according to claim 2, wherein The first anti-static gas suction hoses (4) are all provided with first valves (5), and the gas inlets of the first anti-static gas suction hoses (4) are all provided with filters.

4. The low temperature plasma reaction system for eliminating leaked liquefied petroleum gas according to claim 3, wherein ​ 5. The low temperature plasma reaction system for eliminating leaked liquefied petroleum gas according to claim 2, wherein ​ 6. The low temperature plasma reaction system for eliminating leaked liquefied petroleum gas according to claim 5, wherein ​ 7. The low temperature plasma reaction system for eliminating leaked liquefied petroleum gas according to claim 6, wherein All the first gas outlets are connected with a second anti-static air exhaust hose (6), each second anti-static air exhaust hose (6) is connected with the air inlet of the air exhaust unit one by one, and a condenser (8) is arranged on each second anti-static air exhaust hose (6) to condense liquid products.

8. The low temperature plasma reaction system for eliminating leaked liquefied petroleum gas according to claim 1, wherein The air exhaust unit (2) is provided with a second gas outlet and a third gas outlet, the second gas outlet is connected with the air inlet of the air mixing unit through a third anti-static air exhaust hose (7), a second valve is arranged on the third anti-static air exhaust hose (7), and the third gas outlet is provided with a third valve.

9. The low temperature plasma reaction system for eliminating leaked liquefied petroleum gas according to claim 8, wherein The air mixing unit (3) comprises an air mixing chamber (9) and a blower (10), the air inlet of the air mixing chamber (9) is connected with the second gas outlet of the upper-stage integrated double dielectric barrier discharge plasma reactor (1) through the third anti-static air exhaust hose (7), the air outlet of the air mixing chamber (9) is connected with the first air inlet of the lower-stage integrated double dielectric barrier discharge plasma reactor (1) through the third anti-static air exhaust hose (7), and the air outlet of the blower (10) is connected with the air inlet of the air mixing chamber (9).

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