28 results about "Flammability limit" patented technology

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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

Apparatus and associated methods relate to a neutralization and circulation module (NCM) configured to generate a combustion suppressant stream from a flammable intake stream. In an illustrative example, the NCM includes an intake port and an output port, each in fluid communication with a chamber containing (electro)chemical energy storage units capable of emitting combustible gases. The NCM may, for example, include a reactor in fluid communication between the intake and output port. The reactor may, for example, selectively apply an oxygen-containing stream from an oxygen source to the intake stream to generate, from the stream containing combustible gases, a combustion suppressant gas stream that is discharged through the output port into the chamber such that an upper flammability limit approaches a lower flammability limit in the chamber. Various embodiments may advantageously eliminate a flammable regime in a chemical energy storage environment.

The invention discloses a transformer oil burning and explosion testing device and method, and relates to the technical field of transformer oil burning and explosion test.The transformer oil burning and explosion testing 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 oil body can be heated and ignited at the same time. 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.

The present application relates to the technical field of risk assessment, in particular to a dust and gas coupling explosion risk assessment method and terminal, comprising the following steps: mapping dust gas into a comprehensive stoichiometric ratio distribution, clustering active grids within the explosion limit, analyzing the diameter of the inscribed sphere and the surface ratio of the cluster, screening effective explosion sources, calculating the cumulative volume proportion of effective sources and evaluating the global explosion risk level, in the present application, by constructing a three-dimensional combustion heat weighted mapping model of multi-component medium, heterogeneous monitoring data is converted into a unified stoichiometric ratio field, independent risk clusters are identified by using spatial connectivity analysis, the clusters are geometrically and thermodynamically verified by combining the maximum inscribed sphere diameter and the surface ratio parameter, invalid areas that cannot maintain combustion are removed according to the quenching distance and heat dissipation effect, effective explosion sources are screened, the global risk level is judged, and the accuracy and objectivity of the explosion risk assessment of complex mixed media in a confined space are improved.

The present invention secures sufficient safety even when a flammable refrigerant is used as a refrigerant of an air conditioner. This refrigeration cycle apparatus is provided with: an indoor unit (2) that includes a refrigerant circuit (C) through which a flammable refrigerant circulates, an indoor fan (22), and a refrigerant sensor (23) that detects the concentration of the refrigerant; and a control device (6) that controls the indoor unit (2). When it is determined, as a result of comparison between the concentration of the refrigerant detected by the refrigerant sensor and a preset threshold value, that the concentration of the refrigerant is greater than or equal to the threshold value, the control device (6) controls the indoor fan (22) so as to exhibit an air volume (Q) [m3 / h] and executes mixing operation. When the lower flammability limit (LFL) [kg / m3] of the refrigerant, the assumed leakage rate (W) [kg / h] of the refrigerant, and the assumed suction rate (w) [kg / h] of the refrigerant to be suctioned into the indoor unit (2) are defined, the air volume (Q), the lower flammability limit (LFL), the assumed leakage rate (W), and the assumed suction rate (w) satisfy Q>(W+w) / LFL.

A device and method for testing the explosion limits of low-concentration methane gas extracted at high temperatures based on combustion and explosion pressure, belonging to the field of coal mine safety, is described. The device includes a high-temperature heating chamber, a pressure measurement system, a gas supply system, and a vacuum extraction system. The pressure measurement system is installed at the upper opening of the high-temperature heating chamber and uses a cooling component and a heat insulation component in conjunction with a water-cooled pressure sensor to measure the combustion and explosion pressure of low-concentration methane gas extracted at high temperatures through combustion and explosion. The gas supply system uses a solenoid valve to control a high-pressure mixing tank and injects the mixed gas into the high-temperature heating chamber through a multi-channel compressed gas nozzle from the lower opening. The side opening of the high-temperature heating chamber is sequentially connected to the cooling coil, water-cooled jacket, and vacuum pump of the vacuum extraction system. This device solves the problem of vacuum extraction under high-temperature conditions, enabling repeated measurement of the pressure evolution curve of extracted methane gas from oxidation reaction to combustion and explosion under high-temperature conditions, and accurately obtaining the explosion limits of low-concentration methane gas extracted from coal mines within the range of room temperature to 1200℃.

A lubricant oil, the use of a lubricant oil as an additive, and a method of lubricating parts in an engine are described herein. The lubricant oil 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 of the engine. The minimum evaporation rate is configured so that when at least a portion of the lubricant oil evaporates in combustion cylinder 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 volume are increased, such as during a compression cycle, the probability of a portion of the lubricant oil combusting or auto-igniting is preferably decreased.

The utility model relates to the technical field of well lid, especially an automatic harmful gas exhaust well lid. It mainly aims at the underground pipe trench being easy to generate and accumulate inflammable and explosive harmful gases such as methane and hydrogen sulfide, when the concentration reaches the explosion limit, the fire source or static electricity can cause explosion, and the pipeline is damaged, and the following technical scheme is proposed: the fixed cylinder below the well lid, the first support ring fixedly connected to the inner side of the fixed cylinder, the cover plate set up above the first support ring, a plurality of groups of exhaust holes are formed in the cover plate; the exhaust mechanism is arranged below the first support ring, and the exhaust mechanism is used to exhaust the harmful gas in the pipe trench after starting; the sealing assembly is installed below the exhaust mechanism, the sealing assembly is internally provided with a storage battery, a harmful gas sensor and a control module, sensor data are transmitted to the control module, and the control module controls the start and stop of the exhaust mechanism according to the harmful gas concentration. The utility model can guarantee the safety of the pipeline in the underground pipe trench, eliminate hidden dangers, and protect the safety of ground buildings and pedestrians.