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41 results about "Flammability limit" patented technology

Mixtures of dispersed combustible materials (such as gaseous or vaporised fuels, and some dusts) and air will burn only if the fuel concentration lies within well-defined lower and upper bounds determined experimentally, referred to as flammability limits or explosive limits. Combustion can range in violence from deflagration through detonation.

Porous medium combustor for stable combustion of gas with ultralow heat value

The invention provides a porous medium combustor for stable combustion of ultralow-calorific-value gas, belongs to the technical field of combustors, and solves the problems that an existing combustor is low in heat recycling efficiency and air is not fully preheated before entering a combustion area. The combustor comprises a shell, a gradually-shrunk porous medium layer, a stable-combustion porous medium layer, a gradually-expanded porous medium layer, a premixing chamber, a fuel channel and an oxidizing agent channel, and the gradually-shrunk porous medium layer, the stable-combustion porous medium layer and the gradually-expanded porous medium layer are all located in the shell and are sequentially arranged from top to bottom; the premixing chamber is communicated with the lower part of the divergent porous medium layer; an outlet of the fuel channel is communicated with the premixing chamber; the oxidant channel surrounds the stable combustion porous medium layer and the divergent porous medium layer and is spirally arranged on the shell, an inlet of the oxidant channel is located above the stable combustion porous medium layer, and an outlet of the oxidant channel is communicated with the premixing chamber. The combustible limit of the low-heating-value fuel gas can be widened, stable and efficient utilization of the ultralow-heating-value fuel gas is achieved, and the heat recycling efficiency is improved.
Owner:CHINA UNITED GAS TURBINE TECH CO LTD

Combustible limit value prediction method and application

The invention relates to the technical field of oxygen-enriched combustion safety and flammability limit prediction, and provides a flammability limit value prediction method and application, and the method comprises the steps: obtaining the initial parameters of a gas fuel in a mixed atmosphere of oxygen and carbon dioxide; simulating a combustion process by using an element reaction mechanism, and outputting a curve of component mole fractions changing along with time; the combustion enthalpy change rate under the target atmosphere and the virtual atmosphere is calculated based on the curve, and carbon dioxide in the virtual atmosphere is replaced with virtual gas which has the same thermophysical property but does not have chemical reactivity; respectively calculating combustion heat release, mixture heat absorption and heat radiation; and in combination with the enthalpy change rate and the energy balance equation, the combustible limit value is solved and determined through numerical iteration. By quantifying the chemical effect and thermophysical influence of carbon dioxide, the problem of insufficient precision caused by neglecting the participation of carbon dioxide in reaction and unique thermal property in the oxygen-enriched combustion environment in the existing model is solved, and the method is suitable for the safety design of a combustion system.
Owner:NORTHEASTERN UNIV CHINA

Dual fuel burner and method of operation

The present invention relates to particular combustors, and e.g., to a combustor comprising a central primary fuel lance, a pilot fuel conduit, a primary oxidant conduit, a secondary oxidant conduit, and optionally a secondary fuel conduit, which are arranged in a particular and advantageous manner so as to surround each other at least in their downstream sections. The invention also relates to a furnace comprising the burner and a method of operating the burner. The burner according to the invention provides, in particular, a particularly advantageous way that comprises a pilot burner as part of the main burner in order to ignite a liquid fuel flame in a cold furnace. If desired, the pilot flame may help extend the flammability limit or operating range of the liquid fuel burner.
Owner:AIR PROD & CHEM INC

Inherently safe oxygen / hydrocarbon gas mixer

A method of safely mixing a hydrocarbon with an oxidant is provided. The hydrocarbon and oxidant are saturated with a non-flammable liquid in pre-mix zones that are flooded with the non-flammable liquid and fluidly connected to a common mixing zone that is partially flooded with the non-flammable liquid. The saturated hydrocarbon and oxidant combine within the common mixing zone forming bubbles of a homogeneous gas mixture of hydrocarbon and oxidant, preferably in a ratio of hydrocarbon to oxidant that is outside of the flammability limit, that can exit the non-flammable liquid into a headspace where it can be retrieved for use in an oxidative reaction process such as oxidative dehydrogenation.
Owner:NOVA CHEM (INT) SA

Blended fuel explosion limit rapid prediction and visual platform construction method

The invention discloses a mixed fuel explosion limit rapid prediction and visual platform construction method, and relates to the technical field of explosion limit prediction modeling, and the method comprises the steps: obtaining a multi-source sample data set which comprises the explosion state labels of a plurality of mixed fuels under the conditions of different temperatures, pressures, equivalence ratios and diluent gases; based on the multi-source sample data set, performing training and hyper-parameter optimization on at least one machine learning classification model to obtain a trained explosion limit prediction model; obtaining state parameters of to-be-predicted mixed fuel input by a user through the constructed visual interaction platform, and calling the trained explosion limit prediction model to process the state parameters through the visual interaction platform to obtain an explosiveness prediction result; and carrying out fusion display on the explosiveness prediction result and an explosion limit distribution diagram generated based on the multi-source sample data set on a visual interaction platform. According to the invention, the efficiency and accuracy of mixed fuel explosion limit prediction are obviously improved.
Owner:PEOPLES POLICE UNIV OF CHINA (INT LAW ENFORCEMENT COOP INST OF THE MINISTRY OF PUBLIC SECURITY CHINA PEACEKEEPING POLICE TRAINING CENT)

A compressed air energy storage anti-burning and explosion method for depleted gas reservoirs

PendingCN122097879AInjection and production operations are safe and stable throughout the entire cyclePromote diversityDust removalFire preventionFlammability limitNitrogen gas
The application provides a depleted gas reservoir compressed air energy storage anti-burning and explosion method. The method comprises the following steps: injecting nitrogen as a cushion gas into a target depleted gas reservoir; determining a lower limit value of the amount of nitrogen required for the target depleted gas reservoir to exceed an explosion limit point; determining the injection amount of oxygen-reduced air according to the lower limit value of the amount of nitrogen required for the target depleted gas reservoir to exceed the explosion limit point and the amount of the cushion gas injected into the target depleted gas reservoir, and injecting the oxygen-reduced air into the target depleted gas reservoir according to the determined injection amount of the oxygen-reduced air; wherein when Q 垫 - αQ0 < 0, Q 补充 = αQ0 - Q 垫 ; when Q 垫 - αQ0 > 0, Q 补充 = 0; Q 垫 is the amount of the cushion gas in the target depleted gas reservoir, Q0 is the lower limit value of the amount of nitrogen required for the target depleted gas reservoir to exceed the explosion limit point, and α > 1.
Owner:PETROCHINA CO LTD

Fire-retardant and sound-proof cover device for hydrogen energy equipment

The invention discloses a fire-retardant sound-proof cover device for hydrogen energy equipment, and relates to the technical field of hydrogen energy equipment protection. The sound insulation box comprises a box body, one side of the box body is provided with a flame-retardant assembly, and an inner cavity of the box body is provided with a sound insulation assembly. According to the flame-retardant assembly, the internal hydrogen concentration is monitored through the hydrogen concentration sensor, the motor and the air pump are controlled to be started, the motor drives the blades to close the heat dissipation window, external oxygen is prevented from entering, and the air pump pumps out internal oxygen containing hydrogen and discharges the internal oxygen to a safe position; the whole-process protection from leakage finding to air blocking and hydrogen pumping and discharging can be completed without manual intervention, accurate intervention can be achieved at the initial stage that the hydrogen concentration does not reach the explosion limit through quick response of the hydrogen concentration sensor, the problems of response delay, misoperation and the like possibly occurring in manual inspection are avoided, and the safety and reliability of the inspection are improved. And through the action of directionally and safely discharging the hydrogen-containing air, the new risk caused by secondary accumulation of the pumped and discharged gas in the surrounding environment is prevented.
Owner:CHANGZHOU RUNXIE MACHINERY CO LTD

Compositions and methods for lubricating engine components

PCT designated stageWO2026043680A1AdditivesBase-materialsThermodynamicsFlammability limit
A lubricant oil (104), the use of a lubricant oil (104) as an additive, and a method of lubricating parts in an engine (101) are described herein. The lubricant oil (104) is characterized as having one or more components with each of the components having a minimum evaporation rate when experiencing conditions within a combustion cylinder (102) of the engine (101). The minimum evaporation rate is configured so that when at least a portion of the lubricant oil (104) evaporates in combustion cylinder (102) and locally mixes with the air fuel mixture around it, the concentration of the combustible components in that mixture is greater than the net upper flammability limit of the particular components of the combustible mixture. Thus, in some examples, when the pressure and / or temperature of the combustion cylinder (102) volume are increased, such as during a compression cycle, the probability of a portion of the lubricant oil (104) combusting or auto-igniting is preferably decreased.
Owner:CATERPILLAR INC

Air sealing stop valve of hydrogen fuel cell

The invention discloses an air sealing stop valve for a hydrogen fuel cell, belongs to the technical field of hydrogen fuel cells for automobiles, and aims to solve the problems that after a fuel cell stack is shut down, unreacted hydrogen is usually remained on an anode side, and hydrogen-oxygen mixed gas is extremely easy to form after infiltrated oxygen and hydrogen are mixed, and the system safety is seriously threatened when the hydrogen-oxygen mixed gas is in an explosion limit range. The device comprises a sealing stop valve and a conveying pipe integrally connected with an outlet of the sealing stop valve, an interception sealing device is arranged in the conveying pipe, and the interception sealing device comprises a filtering part, a sealing deoxidizing part and a driving part used for driving the sealing deoxidizing part; the filtering piece comprises a first filtering plate and a second filtering plate; the sealing deoxidizing piece is positioned between the first filtering plate and the second filtering plate. Double protection of physical sealing and chemical deoxidation is realized through the interception sealing device, when the valve is closed, residual air is directly intercepted, and oxygen in an interception area is actively consumed, so that the risk of hydrogen-oxygen mixed explosion is avoided from the source, and the shutdown safety of the fuel cell is improved.
Owner:CHONGQING IND POLYTECHNIC COLLEGE

A method for predicting flammable limit values and applications

The present application relates to the technical field of oxygen-enriched combustion safety and flammability limit prediction, and provides a flammability limit value prediction method and application, which comprises the following steps: obtaining initial parameters of a gas fuel in an oxygen and carbon dioxide mixed atmosphere; simulating a combustion process by using a base reaction mechanism, and outputting a curve of component mole fraction changing with time; calculating a combustion enthalpy change rate in the target atmosphere and a virtual atmosphere based on the curve, wherein the carbon dioxide in the virtual atmosphere is replaced by a virtual gas with the same thermal properties but without chemical reactivity; respectively calculating a combustion heat release, a mixture heat absorption and a heat radiation; and combining the enthalpy change rate and an energy balance equation to determine the flammability limit value by numerical iteration. The present application quantifies the chemical effect and thermal physical influence of carbon dioxide, solves the problem of insufficient accuracy of existing models in the oxygen-enriched combustion environment due to the neglect of the reaction of carbon dioxide and its unique thermal properties, and is suitable for combustion system safety design.
Owner:NORTHEASTERN UNIV CHINA

Separated air inlet type reactor

The utility model relates to a separated gas inlet type reactor, and relates to the technical field of chemical industry production, the separated gas inlet type reactor comprises a reactor body and a catalysis assembly, the catalysis assembly is arranged in the reactor body, and the reactor body is provided with a first gas inlet channel, a second gas inlet channel and a gas outlet channel which are communicated with the interior of the reactor body; and the first air inlet channel and the second air inlet channel are used for introducing combustible materials and combustion improvers respectively, are mutually independent and are introduced into different areas of the catalytic assembly respectively. By designing the two independent air inlet channels, it is ensured that a combustion improver and a combustible material are not directly mixed before making contact with the flame-retardant and explosion-proof metal mesh catalyst layer, and therefore limitation caused by the explosion limit is avoided; on the premise of safety, the chemical reaction can be carried out within the explosion limit, and the reactor efficiency, the reaction conversion rate and the yield are improved.
Owner:SUZHOU TAONE SINCERE NANOMATERIAL TECH CO LTD

Calculation method for fuel mass flow regulation range of gas cannon at different altitudes

The invention relates to a method for calculating the fuel mass flow adjusting range of gas guns at different altitudes. The method comprises the steps that air parameters at the current altitude are calculated; calculating the combustible limit of the gas mixture; calculating the air mass flow output by an air compressor of the gas gun at the current altitude and the fuel mass flow required by the air compressor to output the mixed combustible gas with a certain fuel concentration; and substituting into the previous step to obtain the fuel mass flow regulation range of the gas gun at the current altitude. The method has the advantages that the altitude-atmospheric parameter-combustible limit-fuel flow four-dimensional correlation model is established, and the altitude of the fuel mass flow adjusting range is calculated in a self-adaptive mode in combination with the working characteristics of a gas gun air compressor; the optimal fuel supply quantity at different altitudes is dynamically deduced, it is ensured that the fuel concentration is always within the threshold value for normal work, and the problems that work is unstable and even work cannot be achieved due to reduction of the oxygen density in the plateau / mountain environment can be thoroughly solved.
Owner:NANJING UNIV OF SCI & TECH +1

Fuel Injection Device and Control Method

This invention belongs to the field of valve technology and discloses a fuel injection device and control method. The fuel injection device and control method include a housing, an end cover, a valve seat, a piston, a valve core, a needle valve assembly, and a limiting mechanism. The fuel injection device can inject alternative fuels or diesel fuel. First, the fuel supply in the current operating mode is cut off and inerted. After the previous injection cycle is completed, the fuel supply is shut off, and inert gas nitrogen is introduced and mixed with the fuel to gradually reduce the fuel concentration in the fuel injection device to below the explosion limit, thereby achieving fuel inerting. Under the action of the drive component, the limiting rod is pushed down, thereby pushing the piston down, reducing the volume of the fuel chamber, thereby reducing the volume that needs to be inerted, accelerating the inerting process, and basically removing the residual fuel in the pipeline. Second, under the action of the drive component, the limiting rod is raised to a designated position, and the piston stroke is adjusted to a value corresponding to the injection quantity.
Owner:CSSC POWER INST CO LTD +1

Method and system for determining explosion risk of transformer oil under action of electric arc in oxygen-poor environment

This invention discloses a method and system for determining the explosion risk of transformer oil under the influence of an electric arc in an oxygen-deficient environment. The method includes: collecting free mixed gas generated in the oxygen-deficient space inside a transformer or oil-filled equipment under the influence of an electric arc or thermal fault; directly determining the composition and volume fraction of each component of the mixed gas using a Fourier transform infrared spectroscopy analyzer, wherein the components include at least methane, ethane, ethylene, and acetylene; calculating the lower and upper explosive limits of the mixed gas using the Richardley formula based on the volume fraction of each component; calculating the characteristic gas ratios C2H2 / C2H4 and C2H4 / C2H6, and determining the fault type according to a preset judgment logic based on the changing trend of the acetylene volume fraction; and comprehensively assessing the explosion risk level of the equipment by combining the explosion limits and the fault type. This invention replaces traditional chromatography with infrared spectroscopy analysis, eliminating the need for degassing and providing faster detection speed; it corrects the fault judgment logic using experimental data, compensating for the shortcomings of traditional guidelines under specific operating conditions; and it introduces explosion limit calculation to directly quantify the ease with which the gas can be ignited, providing more intuitive data support for explosion-proof safety.
Owner:SHENZHEN POWER SUPPLY BUREAU

Method for stopping gas production device, and method for producing oxygen gas and hydrogen gas

PendingCN121127634ACellsHydrogen productionElectrolytic agentFlammability limit
In a method for electrolyzing an alkaline electrolyte solution under pressurized conditions, the electrolyte solution flowing out from an anode chamber and a cathode chamber circulates so as to flow into the anode chamber and the cathode chamber again, and the operation of the gas production apparatus is stopped by a step provided with a predetermined step. The gas composition can be prevented from reaching the explosion limit.
Owner:TOKUYAMA CORP

Dual-fuel burner and method of operation

PendingAU2024324725B2ThermodynamicsCombustor
The invention relates to particular burners, and e.g. to a burner comprising a central main fuel lance, a pilot fuel conduit, a main oxidant conduit, an auxiliary oxidant conduit, and optionally a secondary fuel conduit, which are arranged in a particular and advantageous way to surround each other at least in their downstream sections. The invention further relates to furnaces including the burners and methods of operating the burners. Among others, the burners of the present invention allow a particularly advantageous way of including a pilot burner as an integral part of the main burner to ignite liquid fuel flame in a cold furnace. If required, the pilot flame can assist in extending the flammability limit or operating range of the liquid fuel burner.
Owner:AIR PROD & CHEM INC

A porous media combustion device for catalytic pyrolytic combustion of ammonia

The application provides a porous medium combustion device for catalytic pyrolysis combustion of ammonia, in which ammonia is preheated in a catalytic pyrolysis reactor, and is partially pyrolyzed into nitrogen and hydrogen through a heterogeneous ruthenium-free catalyst, and the mixed gas (NH3, N2 and H2) after pyrolysis is introduced into a porous medium combustor to combust after being fully preheated in a premixing zone; the combustion flue gas is used for preheating of ammonia in the catalytic pyrolysis reactor, the flame propagation speed is improved, the combustion stability of the NH3 / H2 / air mixture is increased, and the flammability limit is improved; the high-temperature flue gas generated by combustion is heat-exchanged through a heat exchanger, on the one hand, energy is externally delivered, and on the other hand, through the coupling structure of the heat exchanger and the catalytic pyrolysis reactor, ammonia is preheated to a temperature range of 300 DEG C-500 DEG C and is used for catalytic pyrolysis of ammonia, without external energy input, and the combustion efficiency is improved.
Owner:HUAZHONG UNIV OF SCI & TECH

Explosion limit testing system and control method and device of explosion limit testing system

The invention relates to the technical field of chemical safety, and discloses an explosion limit test system, a control method and device of the explosion limit test system and the explosion limit test system.A mixing unit is arranged in front of an explosion limit tester, so that various gases provided by a plurality of gas supply units can be preliminarily mixed in the mixing unit; and secondary mixing is further carried out by using a gas nozzle. As the mixing unit and the explosion limit instrument are communicated through the mixed gas pipeline, the mixing unit and the explosion limit instrument can be sealed by adopting a static sealing element, and compared with the sealing by adopting a movable sealing element in the related technology, the sealing performance is better, the maintenance cost is lower, and the reliability is higher. And the explosion limit tester can bear higher explosion pressure.
Owner:WANHUA CHEM GRP CO LTD

Intelligent detection and safety protection system for underground harmful gas

The present application relates to the technical field of safety protection system, especially to an underground harmful gas intelligent detection safety protection system. It mainly aims at the problem that underground pipe trench is easy to generate, accumulate harmful gases such as methane, hydrogen sulfide and ammonia, and when the concentration of the harmful gases is in the explosion limit, it will cause explosion when meeting fire source or static electricity, which seriously damages the pipeline and threatens the city operation and personal safety. The technical scheme is as follows: including mutually connected control module and remote communication module, the remote communication module is wirelessly connected to the cloud, the cloud is connected with a control center and a personal terminal, the control center and the personal terminal are mutually connected; the servo motor connected with the control module and multiple groups of harmful gas sensors, the harmful gas sensor is used for monitoring the harmful gas concentration in the pipe trench and transmitting data to the control center in real time; the storage battery. The present application can guarantee the safety of the pipeline in the underground pipe trench, protect the safety of the ground buildings, vehicles and personnel, eliminate hidden dangers and reduce the risk of life and property loss.
Owner:CHENGDU HOLY LAND JIAYUAN ELECTROMECHANICAL EQUIP CO LTD

HVAC system and methods of using the same for leak detection

A method of operating a HVAC system is provided. The method includes removing heat from a working fluid using an evaporator and a blower that moves airflow across the evaporator. The method includes measuring at least one gas property value of a fluid surrounding the evaporator using a leak detection sensor. The method includes determining a control setpoint for a maximum allowable concentration of working fluid in the fluid surrounding the evaporator, where the control setpoint corresponds to a gas property value associated with a threshold percentage of a lower flammability limit of the first refrigerant in air at the operating temperature. The method includes determining that the at least one gas property value of the working fluid exceeds the control setpoint. If exceeded, the method includes closing a value that regulates the flow of working fluid to the evaporator and initiating the blower to move airflow across the evaporator.
Owner:HAS

Systems and methods for flameless combustion

A method of providing flameless combustion includes forming a pre-heated reactant stream in a primary reaction zone by reacting a first stream of fuel and a first stream of undiluted oxidant and maintaining a combustible air / fuel ratio within flammability limits of the fuel. Forming a combustion stream by reacting a first stream of diluted oxidant, a second stream of fuel, and the pre-heated reactant stream in at least one secondary reaction zone downstream of the primary reaction zone. The combustion stream is maintained at a bulk combustion temperature below an auto-ignition temperature of the combustion stream. A composition of the combustion stream and the bulk combustion temperature are adjusted to maintain combustion marginally above a lower ignition limit boundary of the combustion stream. Upon the composition and the bulk combustion temperature reaching pre-determined flameless combustion conditions, the bulk combustion temperature is increased above an auto-ignition temperature of the combustion stream.
Owner:FIVES NORTH AMERICAN COMBUSTION INC

Gas-powder two-phase detonation experiment device and method

The invention discloses a gas-powder two-phase detonation experiment device and method, and relates to the technical field of transformer oil burning explosion testing, the device is improved on the basis of a traditional closed explosion tube, a heating atomization system, an ignition system, a data acquisition system and a synchronous control system are added, directional heating and efficient atomization of an oil body are achieved, and the gas-powder two-phase detonation experiment device and method are high in practicability. Therefore, stable and controllable oil mist steam is actively generated in an experimental environment, and high-precision simulation of the oil mist burning and explosion process under extreme faults in the transformer is realized. The controllable oil mist steam can be actively generated, the limitation of traditional pool fire research is broken through, and the burning and explosion characteristics, such as the explosion limit and the flame propagation rule, in the atomization state are truly represented. All the systems work cooperatively, so that the repeatability and safety of the experiment are improved, and a scientific experiment basis is provided for risk assessment.
Owner:WUHAN UNIV OF TECH

Waste gas incinerator for secondary mixing of waste gas and air

The utility model discloses a waste gas incinerator for secondary mixing of waste gas and air, which relates to the technical field of waste gas incinerators and comprises an incinerator body, a primary air inlet is arranged at the top of the incinerator body, a burner and an annular waste gas distribution device are mounted at the front end of the incinerator body, and a fire damper and a rotational flow plate are mounted in the incinerator body. An annular secondary air distribution device is arranged on the outer ring at the venturi structure of the middle section of the furnace body; according to the waste gas incinerator, waste gas is innovatively scattered into multiple streams to enter the incinerator body, the waste gas is rapidly distributed in air and rapidly away from the explosion limit range, safety is ensured, meanwhile, the air is divided into primary air and secondary air to be mixed with the waste gas, and it is ensured that mixing is more sufficient, and combustion is more complete.
Owner:NANJING YIRE ZONGLIAN ENVIRONMENTAL PROTECTION TECH LIYANG CO LTD

High-efficient emergency recovery method and device for flammable and explosive dangerous chemicals leakage

The present application provides a kind of flammable and explosive dangerous goods leakage efficient emergency recovery method and device, belong to dangerous goods leakage emergency disposal technical field.The method comprises: in the case where the vacuum environment condition of the target recovery scene meets the preset recovery condition, preset volatile inhibiting substance and the to-be-handled flammable and explosive leakage are sequentially controlled to be injected into recovery subsystem;Control recovery subsystem to sequentially execute the mixing procedure of preset volatile inhibiting substance and the to-be-handled flammable and explosive leakage, and the filtration procedure of the flammable and explosive leakage obtained after mixing, and volatile gas generated by filtration is transported to tail gas treatment subsystem;Control tail gas treatment subsystem to execute tail gas treatment procedure to discharge current to-be-discharged substance with the concentration of preset tail gas less than preset tail gas discharge threshold value.Thereby, flammable and explosive dangerous goods leakage efficient emergency recovery and disposal are completed, and the problem of flammable component volatile to form explosion limit, leading to accident escalation is solved.
Owner:CHINA PETROLEUM & CHEMICAL CORP +1

Method for preventing explosion leakage of dust compact produced by converter using dust

The application discloses a method for preventing explosion leakage of dusting ash briquetting used in a converter, and the method is characterized in that: by optimizing the iron mixing mode, the instantaneous pressure generated at the converter mouth is slowed down, and the mixed concentration of CO and O2 in the converter flue gas is controlled to be below the explosion limit. The purpose of the application is to meet the requirement of "no solid waste leaving the factory", reduce the explosion leakage of the positive pressure of the dry deduster by using the dusting ash briquetting, and the application combines the actual production to summarize a method for preventing the explosion leakage of the dusting ash.
Owner:BAOTOU IRON & STEEL (GROUP) CO LTD

Systems and methods for flameless combustion

PCT designated stageWO2025244686A1Staged combustionPulverulent fuel combustion burnersThermodynamicsFlammability limit
A method of providing flameless combustion includes forming a pre-heated reactant stream in a primary reaction zone by reacting a first stream of fuel and a first stream of undiluted oxidant and maintaining a combustible air / fuel ratio within flammability limits of the fuel. Forming a combustion stream by reacting a first stream of diluted oxidant, a second stream of fuel, and the pre-heated reactant stream in at least one secondary reaction zone downstream of the primary reaction zone. The combustion stream is maintained at a bulk combustion temperature below an auto-ignition temperature of the combustion stream. A composition of the combustion stream and the bulk combustion temperature are adjusted to maintain combustion marginally above a lower ignition limit boundary of the combustion stream. Upon the composition and the bulk combustion temperature reaching pre-determined flameless combustion conditions, the bulk combustion temperature is increased above an auto-ignition temperature of the combustion stream.
Owner:FIVES NORTH AMERICAN COMBUSTION INC

A gas control system and method for closed working face in high-gas coal seam

The present invention discloses a gas control system and method for a closed working face in a high-gas coal seam. By changing the mining mode, the traditional mining mode of eliminating gas by ventilation is changed to a closed mining mode, and a sealing mechanism is used to seal the tunnels on both sides, so that the working face area is in a fully closed state. Due to the lack of external ventilation, the gas inside it continues to accumulate as the coal is mined, and the gas concentration greatly exceeds the gas explosion limit, thereby preventing the risks of coal spontaneous combustion, coal dust explosion and gas explosion; personnel cooperate in coal mining in the working cabin and the operating cabin, and transport the coal to the closed floor tunnel for storage, realizing a fully closed-loop process of coal mining, transportation and storage; through the coordinated operation of the gas concentration sensor and the filter, dynamic adjustment of the gas concentration and pressure in the working face is realized; in addition, the pressure relief drilling and microseismic monitoring sensors realize monitoring and early warning of gas outbursts and impact ground pressure in the working face, thereby effectively improving the efficiency of coal mining.
Owner:CHINA UNIV OF MINING & TECH +1

Control device, engine system, skip fire execution determination method, and program

PendingJP2025179717AElectrical controlMachines/enginesThermodynamicsFlammability limit
To provide a control method for avoiding backfire caused by a state of fuel in a cylinder.SOLUTION: A control device acquires a composition of fuel supplied to a cylinder of an engine which combusts an air-fuel mixture obtained by mixing fuel and air and concentration of the fuel in the air-fuel mixture, determines whether or not the acquired composition of the fuel and the acquired concentration of the fuel are within a range of upper and lower limit values of criteria on the basis of criteria information which defines a relation of the criteria set based on the fuel concentration, the fuel composition, and a combustible limit, determines not to execute skip fire of the engine when the fuel composition and the fuel concentration are within the range of the upper and lower limit values, and determines to execute skip fire of the engine when the fuel composition and the fuel concentration are out of the range of the upper and lower limit values.SELECTED DRAWING: Figure 1
Owner:MITSUBISHI HEAVY IND ENGINE & TURBOCHARGER LTD

Oxygen and ammonia gas mixing flow control system and method

The oxygen and ammonia gas mixing flow control system comprises a static mixer, and the input end of the static mixer is provided with a first pipeline assembly used for inputting oxygen and a second pipeline assembly used for inputting ammonia gas. A third pipeline assembly used for outputting mixed gas of oxygen and ammonia is arranged at the output end of the static mixer, the static mixer is connected with the combustor through the third pipeline assembly, and the first pipeline assembly, the second pipeline assembly and the third pipeline assembly are all in communication connection with a PL control unit used for flow control. According to the invention, by comparing the volume percentage of ammonia gas in the mixed gas of oxygen and ammonia gas for combustion test with the explosion limit of ammonia gas in oxygen, a corresponding mixing process (mixing ammonia gas in oxygen or mixing oxygen in ammonia gas) is selected, so that the oxygen and ammonia gas are prevented from reaching the explosion limit in the mixing process; and the operation safety of the system is improved.
Owner:上海舜华新能源系统有限公司

Safety control method and system for hydrogen-mixed natural gas pipeline leakage in comprehensive pipe gallery

The application discloses a kind of safety control method and system of hydrogen-doped natural gas pipeline leakage in comprehensive pipe gallery, by real-time detection hydrogen and methane in comprehensive pipe gallery to obtain gas concentration, and according to the gas of hydrogen-doped natural gas pipeline transportation calculates corresponding explosion concentration threshold and alarm concentration threshold, gas concentration is compared with explosion concentration threshold and alarm concentration threshold, determines leakage level, and different safety control measures are taken for different leakage levels;For the leakage level that can easily cause explosion, nitrogen injection amount is also calculated according to the space volume of gas cabin in comprehensive pipe gallery and gas leakage rate, and nitrogen injection is carried out in the gas cabin in comprehensive pipe gallery according to the nitrogen injection amount.Compared with the prior art, the concentration of leaked hydrogen-doped natural gas in the pipe gallery can be quickly reduced below the explosion limit to ensure the safe operation of the comprehensive pipe gallery.
Owner:SHENZHEN GAS CORP