287 results about "Flame propagation" patented technology

The invention discloses a numerical calculation method for simulating combustion of iron powder group particles, belongs to the field of numerical simulation calculation of iron powder combustion, can perform numerical simulation on single-particle and iron powder group combustion under a microgravity condition, quantitatively analyzes the influence of differential diffusion on single-particle iron powder and iron powder group combustion flame temperature, and improves the calculation accuracy of the single-particle and iron powder group combustion flame temperature. And meanwhile, the influence of iron powder combustion characteristics and flame propagation speeds under different iron powder and oxygen concentration conditions is considered. The method has a certain guiding significance in research on low-propagation-speed lean-burn iron powder flames and subsequent application of iron powder fuel. The microgravity environment can eliminate the influence of convection and buoyancy, so that the combustion process is more stable and predictable, and the basic mechanisms of iron powder combustion, including combustion rate, oxidation process, phase change and the like, can be deeply researched.

The invention discloses a shock wave heat loading high-temperature wind tunnel and a test method, and relates to the technical field of high-temperature wind tunnel test equipment. The shock wave heat loading high-temperature wind tunnel comprises a shock tube, a wind tunnel test system, a pressure acquisition system and an air intake and exhaust system; a high-temperature and high-pressure gas source is obtained in a secondary shock wave reflection heating mode, and the total temperature of the obtained heating gas source is higher; the high-temperature wind tunnel realizes gas heating and pressurization completely through shock wave flow, extra electric power and gas requirements are not needed, and the cost of a single test is lower; the high-temperature wind tunnel test gas is premixed, so that the components of the test gas can be accurately controlled, and the purity of the components of the test gas is ensured; the device can obtain a high-temperature high-pressure subsonic flow field and even a supersonic flow field covering wide-range working conditions, can be used for visualization test diagnosis of spray fuel atomization and spontaneous combustion processes under high-temperature crosswind, accurately characterizes physical and chemical characteristic parameters such as fuel atomization characteristics, self-ignition characteristics, flame propagation characteristics and the like, and has a wide application prospect. And test data support is provided for engine combustion chamber spray atomization combustion organization.

The invention relates to the technical field of fireproof plates, and discloses a flame-retardant fireproof plate material and a preparation method thereof. Modified benzoxazine, an aromatic bromine modified phosphate flame retardant, polyvinyl chloride, lignocellulose and calcium carbonate are mixed, stirred, pressed, maintained and cut, and the flame-retardant fireproof plate material is obtained. Nitrogen and oxygen six-membered heterocycles in benzoxazine form a stable compound at a high temperature to prevent flame propagation; the silicon element promotes carbonization of combustion products to form a carbonaceous layer, and a cross-linked network formed by silicon-oxygen bonds improves the mechanical property of the fireproof plate material; a net-shaped structure formed by boron-oxygen bonds has high flame retardance; hydrogen fluoride generated by the fluorine element can interrupt the combustion chain reaction; aromatic bromine generates hydrogen bromide to cover the combustion surface, so that a flame-retardant effect is achieved; a carbonization layer is formed on the surface of the fireproof plate material through polymetaphosphoric acid generated by phosphate, so that a flame-retardant effect is achieved; the aromatic bromine modified phosphate flame retardant plays a plasticizing role in polyvinyl chloride, and the mechanical property of the polyvinyl chloride is improved.

The invention discloses a high-precision combustible gas detection system, and relates to the technical field of safety monitoring and environmental protection, and the main scheme is as follows: collecting multiple data of combustible gas; respectively calculating a diffusion rate, a combustion heat index and heat conductivity, and further calculating a gas concentration value; comparing a preset threshold value and judging whether the combustible gas concentration is in a normal range or not; if the combustible gas concentration is in a normal range, respectively calculating an explosion lower limit value and an explosion upper limit value to obtain a combustion speed; the flame propagation speed is calculated, and the combustion heat release rate is further obtained; calculating radiant heat flux based on the combustion heat release rate, comparing with a preset threshold value, and judging whether the radiant heat flux is in a safe state or not; according to the method, all-around monitoring and early warning can be carried out on various dangerous conditions related to the combustible gas, and the safety guarantee of the combustible gas use and existence environment is greatly improved.

The invention discloses an in-cylinder combustion process and chemical reaction mechanism-based hydrogen ammonia emission generation prediction system and method, and relates to the technical field of hydrogen internal combustion engine tail gas emission control, and the system comprises an input variable acquisition module, a combustion simulation module, a chemical reaction simulation module, an emission generation prediction module and an output interface module; according to the method, a mechanism-driven multi-physics field coupling prediction system is constructed, the simplified assumption limitation of a traditional empirical model is broken through, high-precision dynamic analysis of the emission characteristics of the hydrogen-ammonia engine is achieved, in combustion process simulation, in-cylinder turbulence mixing and flame propagation details are accurately described by using a CFD model, and in-cylinder combustion simulation is achieved. The chemical reaction module can significantly improve the prediction credibility of unburned fuel residues and pollutant generation through sensitivity analysis and mechanism optimization, in addition, through real-time coupling sensor data and simulation calculation, the abnormal emission trend can be pre-judged in advance, and a feedforward control basis is provided for the ammonia injection amount, the EGR rate and the ignition angle.

The utility model discloses an electric field combustion-supporting jet ignition device and an ammonia fuel engine, and relates to the technical field of internal combustion engines, the electric field combustion-supporting jet ignition device comprises a jet device, an auxiliary electrode, a spark plug and an ammonia sprayer, the jet device comprises a jet device main body and a jet nozzle, and the jet device main body is connected with the jet nozzle to form a pre-combustion chamber; the pre-combustion chamber is communicated with the main combustion chamber; the auxiliary electrode comprises a pre-combustion chamber auxiliary electrode and a main combustion chamber auxiliary electrode, the auxiliary electrode is connected with the control unit through an electrical circuit, and an electric field is formed in the pre-combustion chamber and the main combustion chamber; the spark plug is electrically connected with the control unit through an electrical circuit; and the ammonia spraying device is used for spraying ammonia gas into the pre-combustion chamber through a nozzle outlet of the ammonia spraying device, the ammonia gas is fully mixed with air in the pre-combustion chamber, the mixed gas is ignited at an ignition electrode of the spark plug under the action of an electric field, and the ammonia mixed gas in the main combustion chamber is ignited. Electric field combustion supporting is applied to the jet ignition device, and the combustion reaction rate and the flame propagation speed are increased.

The present application discloses a gas-fired water heater and a control method and control device therefor. The control method comprises the following steps: upon receiving an instruction for propagating a flame to a target combustion unit, obtaining a current fan speed and a current gas proportional valve secondary pressure; adjusting the current fan speed to a flame propagation fan speed FC, and adjusting the current gas proportional valve secondary pressure to a flame propagation secondary pressure CH; during adjustment of the gas proportional valve secondary pressure, maintaining a mapping relationship P=f(r) between the gas proportional valve secondary pressure and the fan speed, keeping the air-fuel ratio of the gas-fired water heater constant within a preset interval, and ensuring that the gas proportional valve secondary pressure at any moment during adjustment is larger than a secondary pressure flameout threshold CH'min corresponding to the fan speed at said moment; and controlling a target staging valve corresponding to the target combustion unit to be opened.

The invention relates to the technical field of cables, in particular to a multi-layer co-extrusion cable based on a low-smoke halogen-free flame-retardant composite layer and a preparation method of the multi-layer co-extrusion cable based on the low-smoke halogen-free flame-retardant composite layer, and the multi-layer co-extrusion cable structurally comprises a conductor layer, a double-layer insulating layer, a reinforced buffer layer and a composite sheath layer from inside to outside in sequence; wherein the double-layer insulating layer comprises an inner layer and an outer layer; the inner layer takes an ethylene-octylene copolymer as a core layer and takes a norbornene dianhydride grafted polyether ester elastomer as a shell layer, so that the material is endowed with high elasticity and impact resistance, and the cracking of the insulating layer is inhibited; the modified nano montmorillonite is dispersed into a nano lamellar barrier, so that heat diffusion is delayed, and low smoke and zero halogen are realized; the outer layer is composed of an ethylene-methyl acrylate matrix and di-tert-butyl phosphinic acid aluminum salt, the di-tert-butyl phosphinic acid aluminum salt is decomposed at high temperature to generate aluminum phosphate, a carbon layer is formed to isolate oxygen heat, and phosphorus-containing free radicals capture active free radicals to interrupt flame propagation.

The invention belongs to the technical field of coal mine safety research, and discloses a fuel-rich gas coal dust explosion residual gas secondary explosion test device which comprises a primary explosion container and a secondary explosion container, the primary explosion container is communicated with the secondary explosion container through a three-phase valve, and the three-phase valve is communicated with a gas sample bag; the pulverized coal spreading system comprises a first spreading machine and a second spreading machine which are fixedly arranged at the bottoms of the primary explosion container and the secondary explosion container in a penetrating manner respectively; the gas supply system comprises a premixing tank which is communicated with the primary explosion container and the secondary explosion container; and the image acquisition system comprises a first camera and a first infrared thermal imager which are arranged corresponding to the first explosion container, and a second camera and a second infrared thermal imager which are arranged corresponding to the secondary explosion container. According to the invention, the research on the flame propagation dynamic characteristic evolution mechanism under the influence of multiple parameters of fuel-rich gas coal dust explosion and residual gas explosion is realized, the experimental error is reduced, and the research cost is reduced.

The invention discloses a low dynamic fatigue type polyurethane elastomer, and relates to the technical field of organic polymer compounds, the low dynamic fatigue type polyurethane elastomer comprises 50-70 parts of polytetramethylene ether glycol, 75-100 parts of 1, 6-hexamethylene diisocyanate, 5-10 parts of a chain extender, 3-8 parts of a dispersant, 1-5 parts of a lubricant, 4-10 parts of a plasticizer, and 6-12 parts of a flame retardant filler. According to the low-dynamic-fatigue type polyurethane elastomer, due to the addition of the flame-retardant filler, during combustion, melamine is decomposed to generate non-combustible gases such as ammonia gas, the gases can dilute the concentration of oxygen and combustible gas in a combustion area and reduce the intensity of a combustion reaction, and meanwhile, phosphorus elements can form substances such as phosphoric acid and metaphosphoric acid at high temperature, so that the flame-retardant property of the polyurethane elastomer is improved. According to the present invention, the polyurethane elastomer and the flame retardant can capture free radicals in the gas phase and interrupt the chain reaction of combustion so as to inhibit the flame propagation, and can promote the char formation during the combustion process to form a compact carbon layer covering the surface of the polyurethane elastomer so as to provide good thermal insulation and oxygen insulation effects;

The invention discloses a single-component flame-retardant silicone sealant and a preparation method thereof, and aims to provide a sealing material with excellent flame retardance, good adhesive force and long weather resistance. Comprising the following raw materials: 30 to 50 parts of alpha, omega-dihydroxy polydimethylsiloxane, 30 to 50 parts of nano calcium carbonate, 1 to 5 parts of a flame retardant, 5 to 15 parts of a flame-retardant filler, 0.3 to 0.5 part of a cross-linking agent, 0.3 to 0.8 part of a coupling agent and 0.02 to 0.05 part of a catalyst. By optimizing the proportion of the components and introducing the specific phosphorus-based flame retardant and the flame-retardant inorganic filler, the sealant can effectively inhibit combustion and delay flame propagation when encountering fire. Meanwhile, the flame-retardant sealant disclosed by the invention also shows excellent mechanical properties and weather resistance, is easy for industrial production and has a wide market application prospect.

A flame suppressor for venting pipelines, vessels or tanks containing a combustible gas includes a quench module and an injector located in a flow path of the vented pipeline product exiting the quench module. The injector introduces an educted jet of a second gas into the flow path so that vented pipeline product has speed above a flame propagation speed of the combustible gas. The second gas may be a non-combustible or inert gas or air and may be used to dilute, as well as accelerate, the vented pipeline product. Or the second gas may inject a combustible gas, for example, methane, still accelerating the vented pipeline product.

A flame mitigation device for flammable liquid containers includes a cylindrical body with vertical fine mesh screens in the air chamber and horizontal fine mesh screens in the fluid chamber. The air chamber and fluid chamber are separated so fluid and air do not mix or interfere with each other whilst fluid is being poured from the bottle, through the flame mitigation device. When attached to a flammable liquid container, the device provides improved fluid flow and prevents flame propagation, ensuring safe storage and handling of flammable liquids.

The invention discloses a plasma ignition and combustion-supporting cooperated cavity stable combustion ammonia burner which comprises a three-stage plasma ignition and combustion-supporting device and a three-stage fuel and air supply system, and the three-stage plasma ignition and combustion-supporting device comprises a first-stage plasma ignition and combustion-supporting device, a second-stage plasma ignition and combustion-supporting device and a third-stage fuel and air supply system. The second-stage plasma ignition and combustion-supporting device, the third-stage plasma ignition and combustion-supporting device and the three-stage fuel and air supply system are respectively a first-stage fuel and air supply system, a second-stage fuel and air supply system and a third-stage fuel and air supply system. The problems of low flame propagation speed, high ignition energy and the like existing in ammonia fuel combustion at present are solved, stable combustion of pure ammonia can be realized under the condition that hydrogen or other fossil fuels are not doped into ammonia gas by adopting a multi-stage plasma ignition and combustion-supporting device, assisting ammonia combustion and combining a bluff body combustion stabilizer, and a three-stage combustion stabilizing technology is adopted, so that stable combustion of pure ammonia is realized. And the stable combustion range of ammonia gas can be greatly expanded.

The present invention relates to the technical field of flame combustion, and discloses a constant-volume combustion device and method for discriminating flame flow states. The device includes a constant-volume combustion bomb cylinder pressure acquisition system and a flame schlieren image acquisition system. The refined pressure fluctuation state in the combustion cylinder is used as a new evaluation index, and then compared and analyzed with the flame front obtained under different working conditions according to the characteristic parameters of the flame flow state, so as to better quantify the influence of pressure fluctuation on the flame development process during flame propagation, and then make a detailed classification of the flame flow state changes due to fluid instability and heat-mass instability. Finally, it can lay a foundation for quantifying the influence of instability on flame propagation during flame propagation, and provide certain theoretical support for subsequent research on the basic theory of flame combustion.

The invention discloses a staged cracking ammonia internal combustion engine system which comprises an ammonia supply system, a first-stage catalytic cracker and a combustion chamber, the combustion chamber is connected with an air inlet channel and an exhaust channel, and a spark plug is installed on the combustion chamber; the ammonia supply system is used for providing low-pressure gaseous ammonia, the ammonia supply system is connected with an inlet of the first-stage catalytic cracker, and an outlet of the first-stage catalytic cracker is connected with the gas inlet channel; the first-stage catalytic cracker is connected with the exhaust passage through an exhaust branch pipe, a low-temperature catalyst for catalyzing ammonia to be decomposed into hydrogen and nitrogen is arranged in the first-stage catalytic cracker, and the inner wall of the combustion chamber is coated with a second-stage ammonia catalyst coating. Staged ammonia cracking is carried out at low temperature and high temperature, a small amount of ammonia is decomposed by the first-stage catalytic cracker to generate hydrogen, the ignition energy of the ammonia can be remarkably reduced by the small amount of hydrogen, and the flame propagation speed of ammonia combustion is increased; the secondary cracking in the combustion chamber efficiently decomposes ammonia through a catalyst coating, so that the oxidation rate and the combustion efficiency of ammonia are improved, and the emission of unburned ammonia is reduced.

The invention discloses a method for predicting the explosion intensity of a steam cloud based on a flame velocity. The method comprises the following steps: constructing a flame propagation prediction formula by integrating factors such as a gas cloud limitation degree, obstacle blockage, steam cloud activity and a flame propagation distance; collecting data in different scenes for fitting analysis, and determining values of undetermined parameters in the flame propagation prediction formula in different scenes; solving a flame propagation prediction formula to obtain a dimensionless flame velocity based on the value of the undetermined parameter in the target scene, and determining an actual flame velocity in combination with the sound velocity; based on the determined actual flame speed, predicting the explosion overpressure through a relational expression between the actual flame speed and the explosion overpressure established in the target scene; based on the predicted explosion overpressure, the explosion impulse is predicted through a relational expression between the explosion overpressure and the explosion impulse established in the target scene; and representing the explosion intensity of the steam cloud based on the predicted explosion overpressure and explosion impulse. The method is simple in process, high in reliability and wide in application range.

In certain embodiments, a significant improvement in H2-ICE performance can be achieved by a combination of active scavenging pre-combustion chamber technology and predictive model-based spark control to overcome the drawbacks of known combustion technologies. In certain embodiments, advanced combustion modeling and simulation of the ignition process, including spark events, arc movement and elongation, and resulting flame propagation, can be used to predict the relationship between spark energy / output, flow within the electrode gap, and flame growth (SOC) for different engines, different spark plugs, and various conditions. This information can be used to adjust the spark energy / output characteristics during the spark event of the same cycle in order to minimize SOC variations and significantly reduce the tendency of combustion anomalies such as backfire, knocking, and pre-ignition that prevent the achievement of high engine output density and efficiency.

The invention discloses a high-temperature-resistant fireproof flexible cable and a preparation method thereof, and belongs to the technical field of fireproof cables, the high-temperature-resistant fireproof flexible cable comprises a first outer sheath, the inner wall of the first outer sheath is provided with a second outer sheath, and the inner wall of the second outer sheath is provided with an armor. The first outer sheath, the third outer sheath, the fourth outer sheath and the fifth outer sheath are designed and are all made of magnesium-containing flame retardant materials, in a magnesium-containing flame retardant performance test, flame spread is low, the released total heat value is low, the tensile strength is high, the smoke density is low, and at the high temperature, magnesium in the magnesium-containing flame retardant can release water due to the chemical characteristic, so that the flame retardant performance is improved. The cable is good for reducing the combustion temperature and inhibiting flame propagation, and has relatively strong fire resistance and high temperature resistance, and when the first outer sheath is combusted, the magnesium-containing flame retardant is generally halogen-free, generates less harmful gas, and is more environment-friendly.

This application relates to the field of kitchen appliance technology, and more particularly to an inner ring burner cap and a gas stove. The inner ring burner cap has an inner ring cavity; ignition holes and flame-preserving holes, respectively communicating with the inner ring cavity, are formed on the side walls of the inner ring burner cap. The ignition holes are configured opposite to the ignition needle, and the flame-preserving holes are configured opposite to the thermocouple; a main burner hole, communicating with the inner ring cavity, is provided at the top of the inner ring burner cap; an ignition groove, communicating with the inner ring cavity, is formed on the outer side wall of the inner ring burner cap, arranged around the axis of the inner ring burner cap, and located between the outlet of the flame-preserving hole and the outlet of the main burner hole. The ignition groove on the inner ring burner cap facilitates the upward propagation of the flame at the flame-preserving hole to form a flame at the main burner hole, enabling the inner ring burner cap to achieve rapid and stable flame propagation, thus improving the user experience.

This application provides a flame-retardant silicone and its preparation method. In this flame-retardant silicone, through the synergistic effect of boron-containing polysiloxane prepolymer and functionalized boron nitride, the flame-retardant silicone has an afterflame time of ≤5s at 800℃, an oxygen index of ≥36%, and has passed UL94V-0 certification. It can quickly form a ceramic barrier layer at high temperatures, effectively preventing flame propagation. The helical structure of the siloxane main chain, combined with the reinforcing effect of functional fillers such as nano-fumed silica, low-melting-point glass powder, and activated inorganic smoke suppressant and flame retardant, makes the tensile strength of the flame-retardant silicone ≥45N, and the permanent tensile modulus retention rate ≥85% under 125% radial shrinkage, exhibiting excellent tear resistance. This flame-retardant silicone is suitable for applications requiring high flame-retardant performance, such as new energy cables and electronic device protection.

This utility model discloses a high-efficiency flame-arresting and explosion-proof valve suitable for dusty gas environments, including a valve body, a valve disc, a counterweight device, and a self-locking device. The valve body includes a valve shell and a top cover plate. Inlet flanges and outlet flanges are provided on the left and right sides of the valve shell. The inner side of the inlet flange extends into the valve body and is equipped with a rubber ring. The upper side of the valve disc is welded to a rotating shaft via a rotating arm. The two ends of the rotating shaft are rotatably connected to the valve body via bearings. The counterweight device includes a counterweight, a slender rod, and a stop rod. The self-locking device is a combination of a spring pin and a locking switch. In the event of an explosion, the high-efficiency flame-arresting and explosion-proof valve provided by this utility model closes the valve disc and is locked by the self-locking device, effectively cutting off the propagation path, achieving flame arrest and explosion isolation, preventing the propagation of shock waves and flames generated by the explosion, effectively preventing secondary and multiple explosions, and effectively protecting the safety of personnel and upstream equipment.

The utility model relates to the technical field of explosion-proof devices, in particular to a coal mine underground electric control automatic explosion-proof device, which comprises an explosion-proof main body, a mounting rack, a sliding rod and a receiving plate, the explosion-proof main body comprises a shell, a gas storage cavity and a mounting frame, high-pressure gas is arranged in the gas storage cavity, a trigger frame is arranged in the mounting frame in a sliding manner, and the receiving plate is arranged in the trigger frame. The trigger frame is fixedly connected with the sliding rod, and the shell is filled with fire extinguishing powder. A sealing structure is arranged in the shell, an electric control assembly matched with the sealing structure is arranged on the shell, the electric control assembly is externally connected with a cloud platform through a wireless module, and the position of the sealing structure is controlled by arranging the electric control assembly, so that whether a gas storage cavity in the shell is communicated with a trigger frame or not is controlled; and when explosion occurs, the sealing structure is controlled to release the sealing state, high-pressure gas enters the trigger frame and sprays out the fire extinguishing powder to extinguish fire, flame propagation is blocked, and loss is reduced.

The invention discloses a zero-low-carbon fuel combustion device based on catalytic heat surface combustion supporting and a control method thereof, and relates to the technical field of aviation power equipment.The zero-low-carbon fuel combustion device based on catalytic heat surface combustion supporting comprises a glow plug suitable for being installed on the wall face of a combustion chamber of an engine and stretching into the combustion chamber of the engine; the protective cover is arranged on the radial outer side of the glow plug, a cavity is formed between the inner circumferential surface of the protective cover and the outer circumferential surface of the glow plug, catalyst layers are arranged on the inner circumferential surface of the protective cover and the outer circumferential surface of the glow plug, a first opening communicated with the cavity is formed in the protective cover, and the first opening comprises a plurality of sub through holes formed at intervals; a second opening is formed between the protective cover and the glow plug; and the injector is suitable for injecting fuel into the first opening. The zero-low-carbon fuel combustion device based on catalytic heat surface combustion supporting has the advantages of being capable of achieving the zero-low-carbon target conveniently, good in ignition performance, high in flame propagation performance, long in service life and the like.

The utility model relates to a multi-sparking plug ignition system, combustion chamber and gas engine, multi-sparking plug ignition system includes precombustion chamber and second sparking plug, precombustion chamber is provided in dome structure center, precombustion chamber is provided with first sparking plug, precombustion chamber is provided with a plurality of jet orifice at interval along the circumference, second sparking plug is provided with second sparking plug. At least one spray hole points to a high-frequency detonation area near an exhaust throat of an exhaust passage in the combustion chamber, the second spark plug and the pre-combustion chamber are arranged between the air inlet passage and the exhaust passage in a spaced mode, and the second spark plug is close to the edge of the dome structure. The high-speed jet jetted by the pre-combustion chamber in the multi-spark-plug ignition system enables flame to reach the edge of the combustion chamber as soon as possible, and the second spark plug can accelerate combustion in the nearby space, so that the multi-spark-plug ignition system can effectively improve the flame propagation speed, shorten the time for the flame to propagate to the edge of the combustion chamber and improve the combustion efficiency. Flame can reach the edge of a combustion chamber of an engine as soon as possible, and the aim of reducing the knocking tendency is achieved.

The application discloses a kind of multi-stage linkage explosion venting test methods combined with powdery combustion inhibitor, it is related to explosion-proof engineering and safety detection technical field;The method is by constructing with explosion venting device, ignition system, powdery inhibitor delivery system and pressure and optical sensor test cabin, uses PLC to realize ignition, pre-delivery, pressure relief trigger, synchronous inhibition and afterflame inhibition and so on multi-stage linkage control;And through pressure, temperature and flame sensor real-time acquisition of multi-dimensional data of explosion process;By before ignition, ignition instant and in the process of pressure relief with different doses of powdery inhibitor, the explosion suppression performance under different linkage strategies can be systematically evaluated;The application can simultaneously obtain peak pressure, pressure rise rate, flame propagation speed and re-burning conditions and other multi-parameters, realize the quantitative evaluation of the explosion suppression efficiency of powdery combustion inhibitor under multi-stage linkage explosion venting conditions, with the advantages of good data integrity, strong repeatability and suitable for standardization explosion-proof test method construction.

The invention discloses a DOPO modified dry water explosion suppressant as well as a preparation method and application thereof, and belongs to the technical field of safe chemistry. Adding a silane coupling agent into the DOPO solution, and stirring to obtain a DOPO type silane coupling agent; the preparation method comprises the following steps: adding a DOPO type silane coupling agent into fumed silica, stirring or carrying out ultrasonic dispersion, filtering and drying to obtain DOPO modified fumed silica, then adding the DOPO modified fumed silica into water or an explosion suppressant solution, and stirring to obtain the DOPO modified dry water explosion suppressant. According to the invention, the dry core material and wall material are modified, so that the explosion suppression performance is obviously improved. Due to the addition of DOPO, the dry water is endowed with good flame retardant property, and flame propagation can be effectively inhibited under the condition of high temperature or a fire source; the composite use of the explosion suppressant enhances the explosion suppression effect of the dry water, a composite material with higher explosion suppression performance is formed, the types of the explosion suppressant can be adjusted according to the actual application environment, and the explosion suppressant can be widely applied to the explosion-proof requirements in different scenes.

The present application belongs to the field of afterburner design, and is an asymmetric afterburner internal step ignition structure, comprising a cone, a support plate and an ignition nozzle; an annular step ignition zone is provided in the middle of the cone, and the step ignition zone comprises a first step zone, a transition zone and a second step zone. During the ignition process of the afterburner, the fuel passes through the fuel nozzle in the first step zone through the casing and the support plate into the interior of the step, and is ignited by the ignition nozzle located at the center of gravity of the first step zone. The oil-gas mixture is first ignited and burned in the first step zone. Since the step angle of the first step zone is 90°, it can produce an obvious sudden expansion effect on the airflow, thereby constructing a stable recirculation zone, and at the same time has excellent flame propagation characteristics. The flame quickly propagates to the transition zone and the second step zone. The setting of the transition zone can make the vortex formed in the first step zone during the flame transfer more stable and will not fall off, thereby realizing fast and reliable ignition of the afterburner.

The utility model discloses a dry-type flame arrester for a coal mine gas conveying pipeline, which relates to the technical field of flame arresting of the coal mine gas conveying pipeline and comprises a shell component, a flame arresting part and a fastener. Through the combined design of the fire-retardant sleeve, the stainless steel wire mesh and the corrugated plate type fire-retardant disc, flame propagation can be effectively blocked, and gas explosion accidents are prevented; the flame arrester adopts the design of the shell assembly and the flame arresting part which are in mirror symmetry, is convenient to install and maintain, and ensures the stability of the structure through the connection of a fastener; the flame arrester is suitable for gas conveying pipelines with different pipe diameters, can meet the use requirements under different pressure conditions, and is wide in application range; when the gas passes through the flame arrester at the average flow speed of 15m / s, the pressure drop is less than or equal to 1kPa, so that the gas conveying efficiency is not influenced; in conclusion, the dry type flame arrester provided by the utility model can effectively solve the explosion problem in a coal mine gas conveying pipeline, insulates flame propagation, ensures the production safety of a coal mine, and has a wide application prospect.

The application provides a hydrogen-doped natural gas explosion characteristic experiment device in a confined space, which comprises a pipeline system and a gas distribution system, the pipeline system comprises a driving pipe, a visible pipe and a test pipe arranged in sequence, the gas distribution system comprises a vacuum pump, an electric control valve group and a gas cylinder pipeline connected with each electric control valve in the electric control valve group, and the gas distribution system is connected with the driving pipe through a gas inlet. The hydrogen-doped natural gas explosion accident characteristic evolution and inhibition experiment of different hydrogen proportions can be carried out, and important characteristic parameters in the deflagration and detonation flame propagation process of the hydrogen-doped natural gas can be recorded.