40results about How to "Suppress explosion" patented technology

The invention belongs to the technical field of extinguishment explosion suppression of an oil tank truck and discloses a dry powder extinguishment explosion suppression system of the oil tank truck. The system comprises a powder storage box with a spraying hole on an oil tank, a control box, a fire detector, a high pressure gas bomb and a bottle head valve arranged on the high pressure gas bomb, the fire detector is electrically connected with the control box, the control box is electrically connected with the bottle head valve, an outlet of the bottle head valve is connected with a main air tube, the other end of the main air tube is connected with a first branch tube, the other end of the first branch tube stretches into the powder storage box, and the first branch tube stretches into an end socket of the powder storage box to be fixedly connected with a blowing powder mixing tube. The dry powder extinguishment explosion suppression system can effectively restrain detonation or explosion caused by accidents of the oil tank truck, is high in extinguishment speed and simple in equipment operation and has performance of installing a structure which has no influences on the oil tank truck. In addition, a reducing valve sends pressure gas in an oil tank to enable the pressure gas, and a user can safely overhaul the oil tank after certain concentration is achieved.

The invention discloses a gas-liquid-dust explosion experiment system for use under multiple working conditions. The system comprises a container main body as well as a material temperature control unit, an inner-layer container temperature control unit, a precise electric spark ignition energy generation unit, a gas concentration testing unit, a humidity control unit, a pressure sensor unit, a flame temperature sensor unit and an air inlet and vacuuming unit which are respectively arranged on the container main body. The system can be used for simulating a complex working condition in which multiple multi-physical fields including the temperature, pressure, impurities, humidity, leaking hole shapes, ignition positions and the like are coupled, determining accurate critical ignition energyvalues of explosion of gas, liquid and dust and finishing the measurement of relevant parameters and can be further used for evaluating the explosion suppression property of explosion suppression materials and verifying an explosion suppression method.

The invention relates to a ventilation and explosion suppression device for a seal ring of a floating roof tank. The ventilation and explosion suppression device comprises an air supply branch pipe which is communicated with the floating roof tank and externally connected with a gas transmission mother pipe, the annular seal ring is arranged between the tank wall of an oil tank and the side wall of a floating roof, the annular seal ring comprises a primary sealing piece and a secondary sealing piece, and the ventilation and explosion suppression device is characterized in that the ventilation and explosion suppression device further comprises a central distributor, a plurality of radial branch gas pipes and a plurality of arc-shaped gas distribution pipes, wherein the central distributor is arranged in the center position above a top plate of the floating roof and communicated with the air supply branch pipe; the plurality of the radial branch gas pipes are arranged between the central distributor and the seal ring and communicated with the central distributor; the plurality of the arc-shaped gas distribution pipes are arranged in the seal ring or an edge floating cabin and communicated with the radial branch gas pipes, and a plurality of exhaust holes or gas jet heads for conveying gas into the seal ring are arranged on the arc-shaped gas distribution pipes; and a gap for exhausting tail gas is arranged between the tank wall and the top end of the seal ring. The whole set of the system has the advantages of simple structure, low cost, and convenience in use and maintenance, thereby being a simple, economic, reasonable, effective and ideal technological way for realizing intrinsic safety of the oil tank.

The invention discloses a gas pumping and releasing pipeline explosion suppression fire retarding device which solves the problems that an existing gas pumping and releasing pipeline has great potential safety dangers. An explosion suppression system comprises a controller, a flame detector and a fire extinguisher. The output end of the flame detector is connected with the input end of the controller. The output end of the controller is connected with the input end of the fire extinguisher. A fire retarding system comprises a shell body and a metal mesh located in the shell body. An explosion venting plate is arranged at the top of the shell body. A gas inlet pipe and a gas outlet pipe are respectively arranged on the left side wall and the right side wall of the shell body. Sealing water drowning the bottom of the gas inlet pipe is arranged at the bottom of the shell body. The shell body on the outer side of the sealing water is provided with a water level sensor and a water level indicator. The water level sensor and the water level indicator are communicated with the sealing water. The gas pumping and releasing pipeline explosion suppression fire retarding device effectively restrict gas explosion of a pumping and releasing pipeline, eradicates occurrence of chain explosion of a pumping and releasing pipe network, is high in fire retarding performance, and has the advantages of being simple in structure, convenient to operate, and low in cost. Moreover, the suppression process is high in speed and effective.

The invention relates to a novel composite gas explosion suppressant which is composed of inorganic filler, a porous mineral material and inorganic phosphorus substances. The components are crushed, uniformly mixed and dried to obtain the gas explosion suppressant. The porous mineral material composite explosion suppressant prepared by the invention has the advantages of fine and uniform texture,low cost, low moisture absorption, high-efficiency explosion suppression, and easiness in industrial production, and can be applied to the field of gas explosion suppression.

The invention discloses an explosion-proof LED (light-emitting diode) lamp and belongs to the technical field of illumination. The explosion-proof LED lamp comprises a lamp body, a lamp holder, a lampcover and an outgoing guide sleeve, wherein the lamp body is connected with the lamp holder through four stop screws; the outgoing guide sleeve is in threaded connection onto the lamp cover; a heat shield is fixedly connected into the lamp cover; a circuit board is fixedly connected into the heat shield; a heat collection housing is fixedly connected into the lamp body; an LED aluminum substrateis fixedly connected with one end, far away from the lamp holder, of the heat collection housing; a plurality of LED lamps are connected onto the LED aluminum substrates; reflection cups are mounted on the LED lamps; a convex lens is further fixedly connected into the lamp body; and a wire is connected between the circuit board and the LED aluminum substrate. According to the explosion-proof LED lamp, the sealability of the lamp body can be improved by collecting heat dissipated from LED light sources; an explosion-proof barrier is provided at last; dust explosion can be inhibited even if a poor sealing situation appears; the safety protection of the explosion-proof lamp is significantly improved; and the probability of safety accidents due to a problem of the explosion-proof lamp is greatly reduced.

The invention relates to an explosion-proof double-layer high-pressure hydrogen storage tank. A tank body of the tank comprises an inner tank and an outer tank which are integrally connected by tank holders; an interlayer between the inner tank and the outer tank is filled with an explosion inhibitor, and the interlayer is provided with an explosion inhibitor inlet and an explosion inhibitor outlet; the inner tank is connected with the outer tank by a pipeline which leads to the outside of the tank, and the pipeline is separated from the interlayer. The storage tank is mainly used for storinghigh-pressure hydrogen. The storage tank can effectively prevent spontaneous combustion of high-pressure hydrogen due to accidental leakage and inhibit gas cloud explosion, and has simple structure and obvious economic advantage.

The invention provides a super-fine water spray combustion and explosion suppression method for combustible gas and dust conveying pipelines. Super-fine water spray with a micron-level particle size is spread rapidly for a long distance along with high speed gas flow in a pipeline, so that the internal humidity of the pipeline is increased, electric charges generated by friction are neutralized and static electricity on the inner wall of the pipeline is eliminated; super-fine water spray molecule groups cover combustible gas and dust mixtures fully to isolate the combustible gas and dust mixtures from oxygen; the super-fine water spray is easy to gasify, thereby absorbing the heat in an ambient environment greatly and inerting the combustible gas and dust mixtures. Super-fine water spray producing devices can be installed and distributed reasonably according to the length and the opening diameter of a pipeline to protect the combustible gas and dust conveying pipelines comprehensively around the clock and eradicate the hidden danger of combustion and explosion.

The invention discloses a compound explosive suppressant and a preparation method thereof for suppressing explosion of low-concentration coalbed methane, and belongs to the technical field of explosion suppression of the coalbed methane. The preparation method includes the steps that firstly, sodium phosphate hydrogen dibasic decahydrate, potassium phosphate hydrogen trihydrate, bicarbonate magnesium, ammonium bicarbonate and calcium silicate are ground into powder respectively; then talc powder and ground powder ate sieved with 200 mesh, and the sieved powder is collected for standby application; the sieved powder is weighed separately according to a certain proportion and added to a dry powder mixer to mix thoroughly and evenly; and finally, the mixed powder is dried, the drying temperature is raised from the room temperature to 40 DEG C at the heating rate of 15 DEG C / h, and after constant temperature drying, the mixture is obtained. Through comprehensive suppressing of various powder materials, explosion of the coalbed methane cannot continue, and finally the purpose of suppressing explosion of low-concentration coalbed methane is finally achieved. The compound explosive suppressant has excellent explosion suppression performance.

An improved tank design incorporates a new shock dispersing filler packet insert. This filler packet is formed from a sheet of foil and exhibits in its unformed shape an expanded foil center and an unexpanded denser border. All of the edges of the foil sheet are then folded inwardly and the filler insert is finally rolled and secured to produce a cylindrical packet having a dense core. Once the fuel tank is filled with these packets, the ballistic shock is dissipated by the distributed dense portions within the tank.

The invention relates to an application of multilayer foamed iron-nickel metal materials and aims to provide an application of the multilayer foamed iron-nickel metal materials in isolation and suppression of gas explosion in order to explore the isolation and suppression conditions of the multilayer foamed iron-nickel metal materials in the aspect of the gas explosion. A method comprises steps asfollows: 2-3 layers of the foamed iron-nickel metal materials are arranged at intervals, the distance between every two adjacent foamed iron-nickel metal materials is 5-20 cm, the thickness of each layer of the foamed iron-nickel metal material is 2-3 cm, porosity of the foamed iron-nickel metal material close to the side of a detonating point is 20-30 PPI, and porosity of the other foamed iron-nickel metal materials is 10-30 PPI. The invention applies to the field of gas explosion suppression and isolation.

The invention discloses a device for suppressing gas explosion and an application method for the device, and belongs to devices and methods for suppressing gas explosion of coal mines. The device comprises a sensor assembly, a controller, a compressed air control switch, an ejector, an extinguishing agent container and a U-shaped water tank; and the sensor assembly is connected with an input end of the controller by a data line, an output end of the controller is connected with the compressed air control switch, the compressed air control switch is mounted at a compressed air inlet of the ejector, the ejector is connected with the extinguishing agent container by a pipeline, and the U-shaped water tank is connected onto a water inlet of the extinguishing agent container. The controller is used for receiving signals of a flame sensor, a temperature sensor and a pressure sensor and issues action commands to the compressed air control switch; one end of the extinguishing agent container is connected with a receiving chamber, and the other end of the extinguishing agent container is connected with the U-shaped water tank; foam extinguishing agents are sucked into the receiving chamber of the ejector, and compressed air is mixed with the foam extinguishing agents in a mixing chamber, so that foam is formed; and the extinguishing agents are ejected via a nozzle towards explosion flame and extinguish the explosion flame.

The present application relates to a method and an apparatus for producing graphite oxide, the method comprising: producing a graphite slurry comprising graphite and sulfuric acid; producing graphite oxide slurry by injecting an oxidizing agent into the graphite slurry to oxidize the graphite; mixing a hydrogen peroxide solution into the graphite oxide slurry; and obtaining graphite oxide from the graphite oxide slurry by means of a filtration membrane apparatus.

The invention discloses a cylindrical lithium ion power battery shell and a manufacturing method thereof, and aims to provide the cylindrical lithium ion power battery shell and the manufacturing method which have good safety performance and have the advantage that the waste battery shell does not cause serious environmental pollution after the produced battery is discarded. In the technical scheme, the manufacturing method comprises the steps of (A) pressing a metal plate with a thickness of 1-5 mm into a cylindrical outer-layer shell; (B) cutting the metal plate with the thickness of 0.1-0.5mm into the required size, pressing 2-4 Z-shaped folding parts with a width of 1-5 mm, rolling or welding a seam to prepare the cylindrical inner-layer shell; (C) pressing the metal plate with a thickness of 0.1-0.5 mm into S-shaped connecting parts, wherein one ends of the 2-4 S-shaped connecting parts are bonded to an outer side of the inner-layer shell by using a conductive adhesive; (D) welding the bottom edge of the inner-layer shell to the bottom of the outer-layer shell, wherein the other ends of the S-shaped connecting parts in the step (3) are bonded to an inner side of the outer-layer shell by using the conductive adhesive; and (E) injecting a foam filling layer between the inner-layer shell and the outer-layer shell. The cylindrical lithium ion power battery shell and the manufacturing method thereof belong to the technical field of chemical power supply.

The invention provides a converter gas flue gas conditioning system and a flue gas conditioning method thereof in order to solve the problems that in the prior art, pollution is heavy and the cost ishigh when a chemical agent is used for flue gas conditioning, and due to the fact that converter gas belongs to flammable and combustible gas, conditioning of the conductivity of flue gas and dust through atomization of compressed air and water is not suitable, and belongs to the technical field of converter gas dedusting systems. The system comprises a water inlet pipeline and a nitrogen pipeline, nitrogen and water or water vapor are mixed to atomize the water, the mixed and atomized water is introduced into an inlet of an evaporative cooler through a pipeline, the atomized water is furthervaporized in the evaporative cooler, water molecules are combined with particles in the flue gas, the conductivity of the dust particles in the flue gas is changed, the dust is easier to charge afterentering an electric precipitator, and the chemical property of the nitrogen is inactive, so that the risk of explosion when the nitrogen makes full contact with the flue gas is avoided.

The invention discloses a high-performance powdery emulsion explosive for a three-level coal mine. The powdery emulsion explosive is prepared from components in parts by mass as follows: 70.0-80.0 parts of ammonium nitrate, 7.0-11.0 parts of sodium nitrate, 7.5-11.0 parts of water, 6.0-10.0 parts of sodium chloride, 1.2-1.5 parts of microcrystalline wax, 3.5-4.8 parts of hydrocarbon, 0.3-0.6 parts of a sensitizing agent and 2.0-2.5 parts of an emulsifier. The invention further relates to a preparation method of the high-performance powdery emulsion explosive for the three-level coal mine. The preparation method is simple and easy, the preparation cost is low, the prepared emulsion explosive is good in explosion performance and good in safety and produces little blasting fume, the explosive body is harder in form, non-sticky and high in water resistance, besides, index variation amplitude within the validity period is smaller, quality and stability of the emulsion explosive are improved, the quality guarantee period is prolonged, and the storage is stable.

The invention provides a lithium battery energy storage cabin safety monitoring emergency system and a lithium battery energy storage cabin safety monitoring emergency method. The lithium battery energy storage cabin safety monitoring emergency system comprises a detection module, a fire extinguishing anti-reburning explosion suppression module, an exhaust explosion-proof module and a control module, the detection module is installed in the battery energy storage cabin and used for detecting fire and combustible gas in the battery energy storage cabin and sending out a fire signal and a combustible gas signal. The fire extinguishing, anti-reburning and explosion suppression module is used for anti-reburning fire extinguishing and explosion suppression of the battery energy storage cabin; the exhaust explosion-proof module is used for emptying combustible gas in the battery energy storage cabin; the control module is used for receiving the combustible gas signal and the fire generation signal sent by the detection module and judging; the opening or closing of the exhaust explosion-proof module is controlled according to the combustible gas signal; and the fire extinguishing anti-after-combustion explosion suppression module is controlled to be opened or closed according to the fire occurrence signal. According to the method, when different types of lithium batteries are subjected to thermal runaway, the thermal runaway of the batteries can be accurately judged, and the problems of missed judgment and delayed judgment are avoided.

The invention belongs to the field of fire extinguishing agents and particularly provides a metal zirconium fire extinguishing agent which comprises the following components in percentage by mass: 30%-32% of modified quartz sand; 32-35% of modified sodium chloride, 20%-23% of ammonium polyphosphate, 2%-3% of magnesium stearate, 3%-4% of hydrophobic silicon dioxide, 1%-2% of vermiculite powder and1% of mica powder. In the fire extinguishing process, chemical fire extinguishing and physical fire extinguishing can be combined, a reaction chain of metal zirconium combustion is cut off, and the good effects of cooling, after-combustion resistance and dust explosion inhibition are achieved. The invention further provides a preparation and use method of the zirconium metal fire extinguishing agent. The preparation method is simple, low in cost, easy to store and convenient to use.

An explosion-suppressing oil tank of the present invention includes a box body, an explosion-suppressing body filled in the box body, and a grid protective cover set outside the oil level sensor, wherein the explosion-suppressing body is set as a porous structure, and the explosion-suppressing body is provided by the bulletin number CN102181756 B is made of the gas station oil tank barrier explosion suppression material aluminum foil; the box body is provided with a grid that divides the box body into two or more chambers, and the explosion suppression body is placed in the chamber; The refueling port of the tank is provided with a refueling shield. Compared with the prior art, the present invention not only can effectively prevent the oil level sensor from being stuck by the explosion suppression body filled in the tank, but also has an oil penetration hole on the surface of the refueling shield so that the oil can smoothly enter the inside of the tank and can effectively prevent The anti-explosion body blocks the filling port, effectively avoiding gun jumping and oil spillage. At the same time, the anti-explosion body effectively controls the gas expansion degree of the fuel tank, so that the pressure in the fuel tank does not change much, and the occurrence of explosion is suppressed.

The invention relates to an environment-friendly explosion-resistant material for rapidly and efficiently inhibiting hydrogen explosion. The explosion-proof material is composed of sodium alginate and sodium silicate and smeared on the outer side of the porous iron-nickel alloy structure in the pipe gallery, hydrogen explosion can be further restrained, hydrogen leakage is reduced, and the possibility of hydrogen embrittlement and hydrogen damage is restrained. The sodium alginate is [C6H7O6Na] n, the sodium silicate is Na2SiO2. 9H2O and Na2O, the content of the sodium silicate is 19.3-22.8% of that of the explosion-proof material, and the ratio of the content of the Na2O to the content of the SiO2 is 1.03 + / -0.03. The material is smeared on the outer side of a porous iron-nickel alloy structure, the defect of the porous structure in space can be overcome, combustion and explosion of the porous structure can be directly and powerfully prevented at the hydrogen leakage position, the explosion resistance effect can be enhanced, and the hydrogen leakage possibility is reduced. The high-temperature-resistant coating is suitable for being smeared on places such as pipe galleries for conveying H2, hydrogen refueling stations, hydrogen storage containers, new energy vehicles existing in limited spaces and the like which have the possibility of hydrogen leakage and have the danger of burning explosion.

The invention provides a system for actively suppressing explosion of toxic or harmful gases, and belongs to the technical field of explosion suppression. The system comprises a vacuum pipeline segment, an inert dust pipeline segment, a gas conveying pipeline segment, pressure induction valves, an air pump, a check valve and a semi-spherical spray head. The toxic gas enters from the left side of the gas conveying pipeline segment and burns on the left side. One pressure induction valve is arranged at the junction between gas conveying pipeline segment and the vacuum pipeline segment, and the air pump maintains a vacuum state in the vacuum pipeline segment at all times. The check valve and the semi-spherical spray head are arranged at the junction between the inert dust pipeline segment andthe gas conveying pipeline segment, another pressure induction valve is arranged at the junction between the vacuum pipeline segment and the inert dust pipeline segment, and the pressure induction valve is connected with the check valve. the system suppresses the explosion of the toxic or harmful gases in the conveying process, thus reducing the severity of accident consequences.

The invention discloses an explosion-proof tank for a fire-fighting robot. The explosion-proof tank comprises a fixed mounting base, an explosion-proof tank, a liquid storage box and a temperature sensor; the fixed mounting base is fixedly connected with a robot; a socket is arranged on the surface of the fixed mounting base; the socket is electrically connected with an action instruction end of the robot; a mounting slot is formed on the fixed mounting base; the explosion-proof tank is arranged on the fixed mounting base through the mounting slot; an insulating explosion-proof layer is pavedon an inner wall of the explosion-proof tank; the explosion-proof tank comprises an upper tank body, a lower tank body, a controller, a wire, a liquid inlet and a liquid outlet; the upper tank body and the lower tank body can be opened and are respectively connected with the controller; the controller is connected with the socket through the wire; the liquid inlet is formed on the top of the uppertank body; the liquid outlet is formed on the bottom of the lower tank body; the liquid storage box is located in the robot and is connected with the liquid inlet and the liquid outlet of the explosion-proof tank; the temperature sensor is arranged in the explosion-proof tank; a display screen of the temperature sensor is arranged on a side wall of the fixed mounting base. The explosion-proof tank is applied to the fire-fighting robot which is used for carrying explosives from fire scenes and guaranteeing personal safety of firefighters.

The invention provides a system for preventing burning explosion of a dust bin, and belongs to the technical field of petrochemical safety. The system for preventing burning explosion of the dust bincomprises a concentration monitoring device, a spark monitoring device, a gas blowing device and a control device; the concentration monitoring device is used for monitoring combustible gas concentration and combustible dust concentration in the dust bin; the spark monitoring device is used for monitoring the intensity of infrared radiation emitted by sparks in the bin; the gas blowing device is used for blowing gas in the bin; and when it is determined that a monitoring value is higher than a certain set threshold value, the control device is used for giving an alarm according to the monitored combustible gas concentration, the combustible dust concentration and the intensity of the infrared radiation emitted by the sparks and controlling the gas blowing device to conduct blowing. According to the technical scheme, and dust explosion can be effectively restrained.

The invention discloses an absorbent capable of reducing concentration of methane. The absorbent is an organic and sequential complex mixture prepared by mixing the following materials in percentage by weight: 0.30 to 1.80% of vegetable oil, 5 to 15% of an anionic surfactant, more than 0% and not greater than 4% of decamethylcyclopentasiloxane, and more than 0% and not greater than 0.1% of activated carbon, and the balance of water. The absorbent disclosed by the embodiment is convenient to use and low in cost; the solubility of methane can be greatly improved, and therefore, the concentration of gas in air can be efficiently and quickly reduced, and as a result, the safety of mine production can be increased.

A multifunctional air cylinder reliable disconnection type nitrogen rapid purging device comprises a shell. A double-function main air cylinder is arranged on the left side of the shell, an air cylinder pipe is arranged in the double-function main air cylinder, and a rapid connector male head is installed at the right end of an outer end pipe. A nitrogen connecting pipe, an anti-explosion nitrogenvalve and a nitrogen pipe are sequentially connected to the lower portion of the left end of the double-function main air cylinder, and a main air source pipe is installed on the nitrogen pipe. The right side of the shell is provided with a self-closing rapid connector female port and is sequentially connected with a gas connecting pipe, an anti-explosion gas valve and a gas pipe, and two lockingcylinders are arranged at the same time. Three time relays and two two-position five-way electromagnetic valves are arranged at the middle lower part of the shell. The self-closing rapid connector male head is combined with or separated from the matched female port through gas reversing of the three time relays and the two two-position five-way electromagnetic valves, and a locking sleeve is driven to complete pulling and resetting locking. In cooperation with opening and closing of the anti-explosion nitrogen valve and the anti-explosion gas valve, the functions of blowing nitrogen into thegas connecting pipe and the gas pipe and stopping blowing are achieved.

The invention provides a combustion and explosion safety control system and a control method for a polyolefin dust bin, and belongs to the technical field of petrochemical safety. The combustion and explosion safety control system for the polyolefin dust bin comprises a concentration monitoring device, used for monitoring combustible gas concentration and combustible dust concentration in the bin;a gas purging device, used for performing purging the gas in the bin; and a control device, used for giving an alarm and controlling the gas purging device to perform purging when it is determined that the combustible gas concentration and the combustible dust concentration in the monitored bin are greater than a certain preset threshold value. According to the technical scheme disclosed by the invention, the combustible gas concentration and the combustible dust concentration in the dust bin are monitored in real time; when the combustible gas concentration and the combustible dust concentration exceed the threshold value, gas purging and inerting are performed on the dust bin through the gas purging device; and the occurrence of dust explosion can be effectively inhibited.

The invention discloses a flame-suppression explosion relief valve, which comprises a valve body, a valve cover and a valve seat, wherein the valve body is provided with a cavity, the valve cover is arranged at the top of the valve body, and the valve seat is arranged at the lower part of the valve body cavity; the valve body cavity is further provided with a powder storage bag, a rupture disk, a pressure rod, a spring seat and a spring; the powder storage bag is arranged at the top of the valve body cavity, is folded in a zigzag shape, and stores a powder explosion suppressor; the rupture disk is disposed between the powder storage bag and the valve seat, the pressure rod is vertically disposed at the top of the valve seat and located below the rupture disk, and the spring seat is disposed above the valve seat and connected with the pressure rod; the pressure rod is sheathed in the spring, which is located between the spring seat and the valve seat, and the valve body between the spring seat and the valve seat is provided with vent holes. The powder storage bag containing the explosion suppressor is arranged in the valve body, so that the flame-suppression explosion relief valve has the functions of automatic exhausting, explosion suppression and explosion flame elimination, has good explosion-proof safety performance, and can stably operate for a long time.

The invention discloses an urban underground utility tunnel system capable of carrying out safety protection by nitrogen. The system comprises a nitrogen supply device (10), a nitrogen conveying pipeline (20) and an underground utility tunnel (30), wherein the nitrogen supply device (10), the nitrogen conveying pipeline (20) and the underground utility tunnel (30) are connected in sequence; the nitrogen conveying pipeline (20) is provided with a nitrogen control valve; and the nitrogen conveying pipeline (20) can convey nitrogen in the nitrogen supply device (10) into the underground utility tunnel (30). The urban underground utility tunnel system capable of carrying out the safety protection by the nitrogen simultaneously has two functions of electric cabin fire extinguishment and naturalgas cabin explosion suppression. Compared with a hot aerosol and superfine dry powder fire extinguishment system, the system disclosed by the invention has the advantages that investment is low and fire extinguishing agents can be permanently stored, do not lose efficacy and do not need to be replaced. Compared with a CO2 fire extinguishment system, the system disclosed by the invention has the advantages of low investment and high safety for people and has an extremely good prospect.