32 results about "Flame speed" patented technology

The invention provides a method for constructing a thickened flame surface model of hydrogen turbulent combustion, which belongs to the technical field of hydrogen fuel engines, and specifically comprises the following steps: modeling a diffusion enhancement effect and a flame surface wrinkle effect caused by multi-scale turbulent flow by constructing a hydrogen fuel turbulent flame speed scale rate under a wide working condition; and the combustion process of the hydrogen fuel can be described more accurately. In addition, on the basis of a thin reaction zone combustion mode, key physical quantities are extracted, a combustion efficiency function is optimized, multi-scale turbulence and a difference diffusion effect are considered, and the thickened flame surface model is further perfected. The development of the method provides powerful technical support for the forward design of the hydrogen fuel engine based on numerical simulation, promotes the engineering application of the hydrogen fuel engine, and assists the hydrogen fuel engine to play a greater role in efficient, clean and safe energy transformation.

A piston (22) for an internal combustion engine (12) includes a piston skirt (64) and a piston crown (70) attached to the piston skirt and including a combustion face (72). The combustion face forms a piston rim (74) and a combustion bowl (78). A bowl rim (82) defines an intersection of the combustion bowl and the piston rim, and a reentry surface (84) defining a reentry angle extends between the bowl rim and the bowl outer wall. A ratio of a bowl depth dimension coincident with the piston central axis to a compressed height dimension coincident with the piston central axis is from about 0.30 to about 0.35.

The invention belongs to the technical field of aviation, and discloses a direct-current brushless oil feed pump with an explosion-proof design structure, which comprises a direct-current brushless motor, and an output shaft of the direct-current brushless motor provides power for an impeller and a small impeller; wherein the impeller is arranged at the tail end of the output shaft, the small impeller is arranged at the middle section of the output shaft, the direct-current brushless motor and the small impeller are arranged in the pump core shell, and the left end of the pump core shell is closed at the right end of the impeller; the inlet valve assembly is arranged on the left side of the impeller, the outlet return valve assembly is arranged in the radial direction of the impeller, and the exhaust port valve assembly communicates with the small impeller. The flame-proof gap formed by the two layers of flame-retardant plate structures arranged at the front end of the motor is utilized, so that when the interior of the motor explodes and flames pass through the flame-retardant plate structures, the flame speed transmission is rapidly reduced, the flame energy is reduced, and the flames are gradually extinguished and cannot be transmitted to a pump inlet, a pump outlet, exhaust gas and an oil tank.

A method and apparatus for operating a flare stack pilot with a fuel having a high flame speed includes a structure which is operable to recirculate products of combustion to be mixed with the incoming fuel to dilute the incoming fuel to reduce the flame speed of the resulting mixture.

The application provides a flame speed and quenching distance testing device and testing method, and belongs to the technical field of combustion testing. The testing device comprises an annular sleeve, a fuel delivery assembly, a central fixed shaft and a plurality of circular ring pieces. The first end of the annular sleeve and the output end of the fuel delivery assembly are in communication. The plurality of circular ring pieces are sequentially mounted on the central fixed shaft along the axial direction of the central fixed shaft. The outer diameters of the plurality of circular ring pieces increase sequentially from the first end to the second end. A first micro-hole for placing a sensor is arranged on the inner ring surface of the circular ring piece. A through hole extending along the axial direction is arranged in the central fixed shaft, and the through hole is used for penetrating the sensor wire harness and for introducing cooling water. A second micro-hole corresponding to the first micro-hole is arranged on the central fixed shaft. The fuel delivery assembly is connected to the annular sleeve and the central fixed shaft for delivering fuel therebetween. The application can simultaneously measure the laminar flame propagation speed and quenching distance of a given mixed gas in one experiment.

The invention provides a rapid construction method for a sustainable aviation fuel combustion reaction mechanism. The rapid construction method comprises the following steps: S1, establishing a physicochemical property data set of various hydrocarbon substances; s2, establishing a cracking mechanism data set corresponding to various hydrocarbon substances; s3, performing model construction on the agent fuel of the SAF; s4, completing reaction mechanism combination of the proxy fuel; s5, verifying the prediction accuracy of the laminar flame speed according to the constructed SAF combustion mechanism; s6, judging whether the accuracy of the numerical simulation result of the laminar flame velocity meets the requirement or not, and if not, improving the proxy fuel model to increase the types of hydrocarbon substances; s7, after the steps are completed and prediction accuracy verification is completed, an SAF combustion reaction mechanism file suitable for numerical simulation work is obtained, mechanism simplification is conducted, and the calculation efficiency of follow-up simulation is improved. According to the method, the time required for constructing the reaction mechanism can be greatly shortened, the work period can be shortened to be within several hours at the fastest, and the SAF types applicable to the combustion mechanism construction method can be expanded.

A piston (22) for an internal combustion engine (12) comprises a piston skirt (64) and a piston crown (70) attached to the piston skirt, which includes a combustion surface (72). The combustion surface forms a piston rim (74) and a combustion bowl (78). A bowl rim (82) defines an intersection between the combustion bowl and the piston rim, and a re-entrant surface (84) extends between the bowl rim and a bowl outer wall, defining an angle of entry. The ratio of a bowl depth dimension coinciding with the piston centerline to a compression height dimension coinciding with the piston centerline is approximately 0.30 to approximately 0.35.

The invention relates to a combustion experiment measurement technology, and aims to provide a turbulent flow constant volume combustion bomb flame velocity measurement device based on laser mie scattering. The device comprises a turbulent flow constant volume combustion bomb, an ignition needle, an ignition control system, an oil drop generator, a high-speed laser, a lens group, a high-speed camera and four fan motor assemblies. The four fan rotating shaft interfaces are arranged on the spherical cavity and are connected to form a regular tetrahedron; the high-speed laser and the lens group are sequentially arranged outside one optical window, and the high-speed camera is arranged outside the other optical window; and the high-speed camera and the high-speed laser are respectively connected to the delay generator through signal lines. The device can simulate a combustion experiment of turbulent flame and chemical reaction coupling under an isotropic uniform turbulent flow field, realizes isotropic turbulent flow fields with different intensities, and is used for researching the interaction of turbulent flame and chemical reaction coupling under different turbulent flow intensities and the influence on the flame propagation speed.

This application provides a method for constructing a thickened flame surface model for hydrogen turbulent combustion, belonging to the field of hydrogen fuel cell engine technology. Specifically, it includes: constructing a hydrogen fuel turbulent flame velocity scaling rate under wide operating conditions to model the diffusion enhancement effect and flame surface wrinkling effect caused by multi-scale turbulence, thus more accurately describing the hydrogen fuel combustion process. Furthermore, based on a thin reaction zone combustion mode, key physical quantities are extracted, the combustion efficiency function is optimized, and multi-scale turbulence and differential diffusion effects are considered to further improve the thickened flame surface model. The development of this method will provide strong technical support for realizing forward design of hydrogen fuel cell engines based on numerical simulation, promote the engineering application of hydrogen fuel cell engines, and help them play a greater role in the efficient, clean, and safe energy transition.

The invention relates to a high-heat-efficiency full-upper-air-inlet gas stove which comprises a stove bottom shell, a burner, an outer air inlet piece, an inner air inlet piece, a stove panel, an air inlet pressure disc, an inner fire cover, an outer fire cover, an inner fire nozzle, an outer fire nozzle and other accessories, wherein the inner fire nozzle and the outer fire nozzle are arranged on a valve. A gradually-shrunk air inlet with a large lower part and a small upper part is processed below a fire hole in the outer fire cover, and the bottom surface of the furnace end outer air chamber is in a gradually-rising spiral shape, so that the resistance of an air path is small, the flame speed is high, and the heat efficiency is improved. The outer fire cover is made of aluminum alloy and polished, so that the outer fire cover is light in weight, small in thermal inertia, capable of reflecting infrared rays to improve thermal efficiency and low in manufacturing cost. A vent hole is formed in the concave side face of the air inlet pressure plate, primary air and secondary air of inner fire are led in through the vent hole, the stove bottom shell is provided with no hole and is of a full-upper air inlet structure, and the influence of opening and closing of a cabinet door is avoided. And air inlet holes with fixed areas are formed in the outer air inlet sheet and the inner air inlet sheet, so that the air inlet sheet and the inner air inlet sheet are stabilized in the optimal working state.

A method of operating a gas turbine engine having a compressor section, a combustion section including a combustion chamber, and a turbine section in a serial flow arrangement, the method comprises providing gaseous hydrogen fuel to a gaseous fuel nozzle assembly fluidly coupled with the combustion chamber; providing steam to the gaseous fuel nozzle assembly. The method also comprises controlling a flame speed of a flame in the combustion chamber by providing the steam from the gaseous fuel nozzle assembly to the combustion chamber.

Fuel compositions comprising: (a) a base fuel suitable for use in an internal combustion engine; (b) a tetraalkylethane compound having formula (I): wherein Ar represents an aryl group and each X is independently selected from a hydrogen atom, a substituted or unsubstituted straight chain or branched C1-C 12 alkyl group, (CH2) n OH or (CH2) n NH2, wherein n is in the range of 1 to 9, with the proviso that at least one of the X groups in each CX3 group is a hydrogen atom. The fuel compositions of the present invention provide improved power and acceleration benefits, as well as increased flame speed and burn duration.

Method for operating an internal combustion engine, wherein the internal combustion engine is operated by an air-fuel mixture comprising a fuel mixture and air, wherein the fuel mixture comprises a first fuel, preferably natural gas, and hydrogen as a second fuel different from the first fuel, whereina hydrogen content of the fuel mixture is determined, andat least an ignition timing is adapted as a function of the hydrogen content of the fuel mixture independent of a target power output of the internal combustion engine,wherein the higher the amount of hydrogen in the fuel mixture the later the ignition timing is set for at least partially compensating a shift of a center of combustion due to higher flame speed of hydrogen compared to the first fuel.

The application relates to the technical field of ignition chamber jet ignition research, in particular to a flame propagation picture recognition processing method for ignition chamber jet ignition. The method comprises the following steps: acquiring a background picture and extracting a to-be-calculated shadow picture; extracting the to-be-calculated shadow picture to obtain a rough extraction picture; deleting pixel points outside a visual range to obtain a fine extraction picture; determining a flame connected region used for calculating the flame speed and the flame filling area of the flame at a moment before the flame touches the bottom of a view window; and calculating the flame speed and the flame filling area of the flame at the moment before the flame touches the bottom of the view window and calculating the flame speed and the flame filling area of the flame at a moment after the flame touches the bottom of the view window. The application solves the problem that in the middle and late stages of jet ignition flame combustion, a particularly bright area appears at the bottom of the view window, the pixels of the bright area are lost, the calculated flame filling area is smaller than the actual value, and the flame area cannot be calculated.

The application discloses a full-premixing intelligent long-lasting lamp suitable for a pure oxygen burner, which comprises a mixer, a mixing pipeline and a combustion nozzle which are sequentially connected, the mixer is connected with a gas inlet pipe and an oxygen inlet pipe respectively, the mixer is provided with an ignition rod which penetrates through the mixer, the mixing pipeline and the combustion nozzle, the mixer is of a Venturi structure, the oxygen inlet pipe is connected to a side wall of the mixer far from the mixing pipeline, the gas inlet pipe is connected to a position with the smallest diameter in the middle of the mixer, and the mixer is provided with an ultraviolet flame detector. The full-premixing combustion is adopted, oxygen and gas are simultaneously introduced into a combustion zone, the flame speed propagation is faster, and almost no nitrogen oxide and carbon monoxide are generated.

The present application relates to combustion experiment measurement technology, aims at providing a turbulent constant volume bomb flame speed measuring device based on laser Mie scattering. The device comprises a turbulent constant volume bomb, an ignition needle, an ignition control system, an oil droplet generator, a high-speed laser, a lens group, a high-speed camera and four fan motor assemblies; four fan shaft interfaces are arranged on the spherical cavity and are connected to form a regular tetrahedron; the high-speed laser and the lens group are arranged outside an optical window in sequence, and the high-speed camera is arranged outside another optical window; the high-speed camera and the high-speed laser are connected to a delay generator through signal lines respectively. The present application can simulate the combustion experiment of the coupling of turbulent flame and chemical reaction under the isotropic uniform turbulent flow field, realize the isotropic turbulent flow field with different intensities, and is used for studying the interaction of the coupling of turbulent flame and chemical reaction under different turbulent intensities and the influence on the flame propagation speed.

This invention relates to a simulation evaluation method for the abrupt change in flame behavior induced by rigid porous materials in gas explosions, belonging to the field of underground gas explosion protection technology in coal mines. The method includes the following steps: First, a two-dimensional slice image of the rigid porous material is obtained through X-ray CT scanning, and a high-precision three-dimensional digital model is reconstructed. Then, an FGM combustion model is constructed using the Chem1D tool combined with detailed chemical reaction mechanisms. During the simulation, key characteristics such as flame velocity, explosion overpressure, and flame temperature are acquired, and the flame propagation mode and abrupt change behavior are analyzed to evaluate the barrier performance of the porous material. This invention has significant advantages such as safety, efficiency, low cost, and no need for expensive experimental equipment. Through numerical simulation, the protective effect of different materials in gas explosions can be accurately evaluated, filling the gap in evaluating abrupt changes in flame behavior through numerical simulation, and providing reliable theoretical support and technical basis for mine safety prevention and control.

The utility model discloses an ammonia and hydrogen mixed pulverized coal MILD combustion system which comprises a boiler, an ammonia fuel inlet and a hydrogen fuel inlet are formed in the lower middle portion of the boiler, and the hydrogen fuel inlet is located below the ammonia fuel inlet. The ammonia fuel inlet is connected with an ammonia supply system, and the hydrogen fuel inlet is connected with a hydrogen supply system; and an SCR denitration device is arranged at the tail part of the boiler. According to the utility model, flameless combustion and ammonia combustion are combined, so that low-nitrogen combustion of NH3 is expected to be realized; hydrogen is mixed, water vapor is generated through combustion, the volume fraction of NOx can be reduced to 10 <-5 >-10 <-4 >, and the combustion stability is ensured by reducing the ignition delay time of ammonia flames, improving the flame speed of ammonia laminar flow and improving the heat release rate; the system disclosed by the utility model can be applied to various occasions such as fire coal, fuel gas and biomass power generation, and has the characteristics of high combustion efficiency, less pollutant emission and the like.

The application discloses a numerical calculation method of hot loss and differential diffusion of swirl hydrogen turbulent combustion, and belongs to the field of numerical calculation of swirl hydrogen turbulent combustion. The method establishes a swirl model containing a mixing fraction, a progress variable, a normalized enthalpy and a second-order control equation of the mixing fraction; simulates the heat loss / gain based on the reactant temperature adjustment of a counterflow flame device, constructs a small flame table in combination with a non-unit Lewis number assumption; maps parameters to a four-dimensional space to generate a small flame library; obtains thermochemical quantities by looking up a table after solving the control equation, and adopts a PIMPLE algorithm for iterative convergence. The application can accurately predict the double-swirl hydrogen flame velocity field and temperature distribution by comprehensively representing the heat loss and differential diffusion effect through the four-dimensional parameter space, and provides an efficient simulation tool for the optimization of a swirl burner.

Various embodiments described herein are related to a flame mitigation device that can comprise a rigid body comprising a side wall having a first perforation of a first size and a second perforation of a second size. The rigid body can be hollow and the first size can be greater than the second size Also, the first perforation and the second perforation can provide fluid communication through the side wall. Moreover, the flame mitigation device is configured to absorb enough heat to drop a burning air / fuel mixture below its auto-ignition temperature at a flame speed between 4 and 6 meters per second.

The invention discloses a natural gas-hydrogen dual-fuel low-nitrogen combustion self-adaptive regulation and control system, and relates to the technical field of proportional mixed combustion systems. The system comprises a control unit, a combustion characteristic detection unit, a self-adaptive regulation and control unit, a fuel supply unit, a three-stage turbulent burner unit and a carbon capture and resource utilization unit. The combustion characteristic detection unit collects flame speed, concentration and boiler load data in real time, the self-adaptive regulation and control unit is coupled with the data to calculate the optimal hydrogen mixing proportion, the fuel supply unit accurately mixes fuel according to instructions, and the three-stage turbulent burner unit achieves low-nitrogen stable combustion. And the carbon capture and resource utilization unit supplies low-carbon hydrogen and cyclically produces methanol. The system can adapt to fuel mixing and load fluctuation, solves the problems of unstable combustion, standard exceeding, high catalyst cost, incomplete carbon emission reduction and the like, and realizes low-carbon and low-nitrogen operation of the industrial boiler.

The invention discloses a combustor with a stepped dune standing vortex imitating structure fire hole plate and a method, and relates to the technical field of combustion equipment. Comprising a fire hole plate, a distribution cavity and a mixing cavity, two rows of fire hole groups are arranged on the fire hole plate, and a stepped sand dune trapped vortex imitating structure is arranged at the connecting part between the fire hole groups and comprises an extension section, a first-stage structure and a second-stage structure which are sequentially arranged in the gas flowing direction. According to the structure, flame airflow is guided through the asymmetrical windward face and the sliding face, a stable standing vortex is formed, flames and secondary air are promoted to be mixed step by step, the combustion temperature is lowered, and emission of nitric oxide and carbon monoxide is reduced. And meanwhile, high flame speed and backflow risks caused by hydrogen-doped combustion are effectively restrained, heat exchanger overheating caused by too high flame is prevented, and the combustion stability is improved. The device is suitable for safe, efficient and clean combustion under the working conditions of pure natural gas and high hydrogen doping ratio.

Method for operating an internal combustion engine, wherein the internal combustion engine is operated by an air-fuel mixture comprising a fuel mixture and air, wherein the fuel mixture comprises a first fuel, preferably natural gas, and hydrogen as a second fuel different from the first fuel, whereina hydrogen content of the fuel mixture is determined, andat least an ignition timing is adapted as a function of the hydrogen content of the fuel mixture independent of a target power output of the internal combustion engine,wherein the higher the amount of hydrogen in the fuel mixture the later the ignition timing is set for at least partially compensating a shift of a center of combustion due to higher flame speed of hydrogen compared to the first fuel.

The present invention relates to a heating system and to a control method of controlling a heating system for heating a primary gas flow through a flow duct, the system comprising: an in-duct burner comprising at least one fuel intake manifold provided with at least one injector, the at least one injector is arranged to inject fuel into the pre-mixing circuit through the injection outlet; and a control assembly arranged to supply fuel to the combustor and configured to allow control of at least one fuel injection parameter, the control method and variation in the cross-sectional flow area of the premix circuit are configured such that the flow velocity of the airflow portion at the injection outlet is greater than the flame velocity of the fuel in the outlet region.

The invention discloses a high-temperature lean-burn methanol engine and a combustion control method thereof, and relates to the technical field of methanol internal combustion engines. Comprising an air cylinder body, an air cylinder cover fixedly connected with the air cylinder body and a piston connected with the air cylinder body in a sliding mode, the air cylinder body, the air cylinder cover and the piston form a combustion chamber, the top of the piston is provided with an asymmetric vortex groove and a flow guide boss, and the top of the inner wall of the air cylinder body is provided with a composite turbulent flow structure. The invention further provides a combustion control method which comprises the steps that combustion parameters such as turbulence intensity in the combustion chamber are calculated according to the rotating speed of the engine, the load working condition and the geometric dimension of the structure; and based on a turbulent flame speed prediction model, oil injection and ignition parameters are reversely calculated, so that the two-stage injection process is dynamically optimized and controlled. Through deep coupling of the structure and the control method, it can be guaranteed that the engine has the high enough combustion heat release rate, and therefore high heat efficiency and low emission are both considered.

The present application relates to the technical field of spraying machine, in particular to a rotary aluminum profile spraying equipment, which comprises a rotary platform and a spray gun body, the rotary platform is provided with the spray gun body, further comprises a combustion chamber, an adjusting assembly, a baffle, a control assembly and a spray pipe, the adjusting assembly is installed above the flame flow channel, the deflection angle of the baffle increases synchronously with the powder input, the adjusting assembly controls the powder input through the angle of the baffle rotation, the control assembly synchronously couples the powder input and the flame speed through the baffle rotation and the adjusting assembly, the control assembly is provided with the spray pipe below, the equipment adjusts the speed of the flame flow according to the powder input into the spraying equipment, ensures that the powder input and the flame speed are coupled in the same proportion, so that the powder can be fully melted, and in turn avoids the pitting phenomenon on the surface of the aluminum profile.

The application discloses a burner for fuel combustion and a combustion method thereof. The burner comprises a primary oxidant-fuel delivery assembly, a secondary oxidant delivery assembly and a tertiary oxidant delivery assembly. The secondary oxidant delivery assembly and the tertiary oxidant delivery assembly are arranged on the same side of the primary oxidant-fuel delivery assembly, and the secondary oxidant delivery assembly is located between the tertiary oxidant delivery assembly and the primary oxidant-fuel delivery assembly. The application combines the staged and dilution combustion technologies, so that the burner has a wide flame adjustable range, realizes the adjustment of a flame combustion position, a flame speed range, a flame local atmosphere and a flame length, and can effectively reduce the generation of NOx, and meanwhile, a high heat transfer efficiency is achieved.

Fuel composition comprising: (a) a base fuel suitable for use in an internal combustion engine; (b) a tetraalkylethane compound having the formula (I): wherein Ar represents an aryl group and each X is independently selected from a hydrogen atom, substituted or unsubstituted, straight chain or branched C1-C12 alkyl group, (CH2)nOH or (CH2)nNH2, wherein n is in the range of 1 to 9, provided that at least one of the X groups in each CX3 group is a hydrogen atom; and c) an alkylbenzene compound having the formula (II) wherein each R1-R6 group is independently selected from hydrogen and a C1-C15 alkyl group, wherein at least one of the R1-R6 groups is a C1-C6 alkyl group. The fuel composition of the present invention provides improved power and acceleration benefits, as well as increased flame speed and burn duration.

The invention discloses a rotational flow hydrogen turbulent combustion heat loss and differential diffusion numerical calculation method, and belongs to the field of rotational flow hydrogen turbulent combustion numerical calculation. The method comprises the following steps: establishing a rotational flow model containing a mixed fraction, a progress variable, normalized enthalpy and a mixed fraction second-order control equation; adjusting reactant temperature to simulate heat loss based on a hedging flame device, and constructing a small flame table in combination with a non-unit Lewis number hypothesis; mapping the parameters to / / / four-dimensional space to generate a small flame library; and after solving the control equation, looking up a table to obtain a thermochemical amount, and carrying out iterative convergence by adopting a PIMPLE algorithm. According to the method, the heat loss and the difference diffusion effect are comprehensively represented through the four-dimensional parameter space, the velocity field and the temperature distribution of the double-swirl hydrogen flame can be accurately predicted, and an efficient simulation tool is provided for optimization of the swirl burner.