26 results about "Propagation rate" patented technology

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

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

The invention discloses a coal mine goaf spontaneous ignition joint detection experiment device and application thereof. The device comprises a goaf spontaneous ignition simulation experiment unit, a goaf sinking compaction simulation experiment unit, a fire source positioning unit and a tracer gas goaf air leakage channel analysis unit. All the simulation experiment units achieve information collection and simulation of different purposes, and after all the units are coupled, experimental research on goaf coal spontaneous combustion influence factors is achieved. According to the joint detection experiment device for spontaneous combustion in the coal mine goaf, a coal spontaneous combustion area is positioned according to the characteristic that waves respond sensitively to density change in a coal body: an ultrasonic probe is adopted to capture cracks after coal spontaneous combustion to form sound waves, and the propagation speed and the propagation time are obtained through signal processing and a display; three-dimensionally capturing and positioning a coal spontaneous combustion area; a temperature sensor assists in positioning the position of an ignition area; by injecting tracer gas krypton, an air leakage channel is determined, and the influence of the air leakage channel on coal spontaneous combustion is judged.

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

The 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 present invention relates to a flame stabilization structure for an efficient burner, which includes a flame hole plate. A plurality of main flame holes are formed on the flame hole plate. The main flame holes are long strip-shaped holes, and the plurality of main flame holes are arranged in parallel at intervals. Flame stabilization holes are provided on both sides of the main flame holes. The flame stabilization holes are long strip-shaped holes parallel to the main flame holes, and the opening plane of the flame stabilization holes is perpendicular to the opening plane of the main flame holes. In the present invention, the flame stabilization holes are arranged along the length direction of the main flame holes, directly heating the root of the main flame holes, accelerating the flame propagation speed of the main flame holes, and enabling the combustion to occur in the air-gas mixed gas close to the flame port plane, realizing stable combustion of the flame. The flame stabilization method of the flame stabilization holes in the present invention is perpendicular cross flame stabilization between the flame stabilization holes and the main flame holes, with uniform and efficient flame stabilization effect.

This invention discloses a method and system for analyzing the steady-state of a laminar diffusion jet flame, relating to the field of gas turbine combustion technology. The method includes: obtaining the instantaneous propagation velocity of the laminar jet diffusion flame when the flame root reaches its final stable position during propagation towards the nozzle. S d and the local airflow velocity at that location U G ;according to S d and U G Determine the instantaneous combustion rate; compare the instantaneous combustion rate with... U G If the difference between the two is within a preset range, it indicates that the combustion rate and the local airflow velocity are in dynamic equilibrium, and it is determined to be a pusher flame; if the instantaneous combustion rate is greater than 1, it indicates that the combustion rate and the local airflow velocity are in dynamic equilibrium, and it is determined to be a pusher flame. U G If the difference exceeds a preset range, it indicates that the flame propagation and the extinction caused by heat loss are in equilibrium, and the flame is identified as an attached flame. This invention achieves precise identification of the flame's stable state by quantifying the comparison between combustion rate and airflow rate, providing a quantitative basis for combustion adjustment and significantly reducing operational blindness and time costs. A corresponding analysis system is also provided.

The invention discloses a combustion flame propagation velocity recognition method based on deep learning. The method comprises the following steps: step 1, acquiring continuous video frames of combustion flame; 2, performing flame region detection on each frame of image by adopting a YOLOv5s model, and outputting a flame bounding box; 3, inputting the flame bounding box image into a DINOv2 model to extract a feature vector, and judging the validity of the flame image through an MLP classifier; 4, a combustion flame image is extracted from the effective flame image, Canny edge detection is conducted on the combustion flame image, and the flame surface area is calculated in combination with tail flame removal and piecewise function fitting; and step 5, tracking flame front displacement in continuous frames through an ORB feature point matching algorithm, and calculating flame propagation speed in combination with a time interval. The invention further discloses a combustion flame propagation velocity recognition system based on deep learning.

To determine abnormality in fuel, such as contamination with incompatible fuel or degradation due to aging, used in an engine-driven work machine.SOLUTION: In a method for determining fuel abnormality in engine-driven work machine, a predetermined characteristic value (for example an ultrasonic propagation speed) of fuel in use detected at any location (fuel tank 80) in a fuel supply system is acquired as a fuel characteristic value Y (S3) and the fuel characteristic value is compared with a fuel characteristic standard range (Ymin to Ymax) which is preliminarily stored in storage means 21 and represents a range where the characteristic value (ultrasonic propagation speed) of the fuel in use is determined to be normal (S5). When the fuel characteristic value Y is out of the range (Y<Ymin or Y>Ymax) of the fuel characteristic standard range (Ymin to Ymax) of the fuel in use, as a result of comparison (No in S6), the fuel is determined to have abnormality (S9), a warning is issued (S10), and an engine operation is restricted (S11).SELECTED DRAWING: Figure 3

The invention discloses a hearth flame detection and combustion control method and device, equipment and a medium, and the method comprises the steps: obtaining a flame image at a fire observation hole of a target hearth, and separating a flame region in the flame image from a hearth wall surface; extracting an ultraviolet branch, a visible light branch and a near-infrared branch in the flame area; outputting a flame stability index based on the ultraviolet branch, the visible light branch and the near-infrared branch; determining a flame propagation speed; constructing an optimal control function according to the flame stability index and the flame propagation speed; and under a preset constraint condition, solving the optimization control function to obtain an optimal control target. The invention belongs to the field of hearth flame control. According to the method, the flame stability can be evaluated, and the combustion strategy can be adjusted.

The present invention discloses a numerical calculation method for simulating the combustion of iron powder group particles, which belongs to the field of numerical simulation calculation of iron powder combustion. The present invention can perform numerical simulation on the combustion of single particles and iron powder groups under microgravity conditions, quantitatively analyze the influence of differential diffusion on the flame temperature of single iron powder particles and iron powder groups, and consider the influence of iron powder combustion characteristics and flame propagation speed under different iron powder and oxygen concentration conditions. The invention has certain guiding significance for the study of lean-burn iron powder flames with low propagation speeds and the subsequent application of iron powder fuel. The microgravity environment can eliminate the influence of convection and buoyancy, making the combustion process more stable and predictable, and helping to conduct in-depth research on the basic mechanism of iron powder combustion, including combustion rate, oxidation process and phase change.

The present invention relates to a strut flame stabilizer with a combination of vortex generators and cavities. The strut flame stabilizer is composed of a leading edge, a straight section, and a V-shaped bottom surface. Structures combining vortex generators and cavities are arranged on both side surfaces of the straight section. The advantages and beneficial effects of the present invention are as follows: When the afterburner adopts the strut flame stabilizer with a combination of vortex generators and cavities, it has good flame stabilization performance, a high flame propagation speed, small flow resistance loss, and high combustion efficiency.

The application discloses a small-scale visual hydrogen explosion monitoring system and a monitoring method, and belongs to the field of hydrogen explosion monitoring.The application comprises an explosion pipeline system, a gas distribution system, an ignition system, a test and data acquisition system.Through forming sodium chloride crystals in the pipeline, based on the flame color reaction of sodium, the invisible hydrogen flame in the ultraviolet wave stage is colored, further, the sodium lamp is used to deepen the flame color, the capture ability of a high-speed camera on the flame form and position is improved, the hydrogen flame propagation speed can be calculated more accurately, the relationship between the hydrogen flame form and the flame propagation speed is analyzed, and the propagation law of pressure and flame is quantitatively characterized; based on a semiconductor laser, the ignition and initiation at different positions in the pipeline can be realized by using the high-thermal-conductivity characteristics of copper, and the dynamic change characteristics of the bidirectional flame propagation with time are analyzed.The application can predict the space-time evolution law of hydrogen combustion and explosion in a confined space, and provide support for safety design, accident prevention and control and the like of hydrogen-related industries.

The present invention relates to a ribbed wavy trailing-edge strut flame stabilizer, which is composed of a leading edge, a straight section, and a V-shaped wavy trailing edge. Three to five pairs of trapezoidal ribs are arranged on both side surfaces of the straight section. The advantages and beneficial effects of the present invention are as follows: When the afterburner adopts this ribbed wavy trailing-edge strut flame stabilizer, it has good flame stabilization performance, fast flame propagation speed, small flow resistance loss, and high combustion efficiency.

The invention discloses an electrolyte fire sensitivity experiment method, and relates to the technical field of fire protection, and the method comprises the steps: setting a plurality of ignition sources according to the concentration data of a gas-liquid mixture, carrying out the ignition according to the energy gradient from low to high, and generating the minimum ignitable energy and the ignition source parameter data; carrying out an ignition experiment on the minimum ignitable energy and the ignition source parameter data, recording flame propagation speed, ignition delay and combustion duration, and generating combustion process time sequence data; arranging and analyzing the time sequence data of the combustion process, calculating a fire sensitivity index, and repeating experiments under the conditions of different cavity temperatures, ventilation speeds, electrolyte volumes and ignition source types to generate multi-condition fire sensitivity data; and sorting and analyzing the multi-condition fire sensitivity data to generate a fire sensitivity evaluation result. The method provides a scientific decision basis for safety assessment and electrolyte design.

The invention relates to a method for calculating a flame propagation process of a solid engine, which comprises the following steps of: judging a grid boundary state of a solid propellant, performing source item mass addition on a grid when the grid meets an ignition criterion condition, simulating surface ignition of the propellant, establishing a multi-factor driving ignition criterion, and introducing flame propagation process correction to calculate the flame propagation process of the solid engine. According to the method, control over the flow field flame propagation process in the solid engine is corrected, the problem that the flame propagation speed in a traditional calculation method is higher than the actual situation is solved, accurate prediction of the solid engine ignition transient flame propagation process is achieved, and technical support is provided for related research of solid engine flame propagation and the like.

The present invention discloses an air film protection type premix burner, comprising a shell, an outer ring groove, a mixed gas ring groove, and an inner ring groove arranged from outside to inside and opening to the right are arranged on the shell, a first air inlet, a mixed gas inlet, and a second air inlet are respectively connected to the outer ring groove, the mixed gas ring groove, and the inner ring groove on the shell, and an igniter is also included, the igniter is connected to the shell, and the head of the igniter is arranged on the inner side of the inner ring groove. The mouth of the mixed gas ring groove sprays out the mixed gas, and the mouths of the outer ring groove and the inner ring groove form outer and inner air films respectively; when the speed of the mixed gas is less than the flame propagation speed, there is a risk of flashback, and the outer and inner air films can separate the mouth of the mixed gas ring groove from the combustion field in the kiln to prevent flashback; the outer and inner air films increase the speed of the mixed gas through the induced effect to prevent flashback; when the air flow speed of the mixed gas is greater than the flame propagation speed, there is no risk of flashback, and the outer and inner air films are conducive to improving the combustion efficiency.

The invention relates to a combustion system, a combustion device, a combustion plate and a design method thereof.The combustion plate comprises a first combustion hole, the first combustion hole comprises a throat section and a flaring section, and the flaring section is located on the downstream of the throat section in the gas flowing direction; and the ratio of the sectional area of the air outlet end of the throat section to the sectional area of the air outlet end of the flaring section is 0.1-1. The design method of the combustion plate comprises the steps that the preset number N of the first combustion holes is obtained according to the preset total flow Q, the preset total flow velocity V and the preset diameter D of the first combustion holes; n is rounded to obtain a corrected actual number M; and the total area of the first combustion holes after correction is obtained. The combustion device comprises the combustion plate. The combustion system comprises the combustion device. According to the combustion system, the combustion device, the combustion plate and the design method thereof, the flame separation phenomenon is avoided, it is guaranteed that the gas flow speed of the throat section is larger than the turbulent flame propagation speed, and backfire is avoided.

The invention discloses a table establishing method for simulating turbulent flow heat diffusion unstable hydrogen combustion, and belongs to the field of hydrogen turbulent flow combustion numerical simulation calculation. On the basis of a multi-component space model (CSM), a small flame model containing a difference diffusion effect, curvature and a strain rate is established, an original solution of the small flame model is mapped into a component space to establish a small flame table, and the influence of the curvature and the strain rate on turbulent flow thermal diffusion unstable hydrogen combustion characteristics is considered at the same time. According to the method, the thermochemical variables in the small flame table are directly extracted according to the space components, and direct calculation in numerical simulation is avoided, so that the calculation cost is reduced. The method has certain guiding significance in researching the application of low-propagation-speed turbulent heat diffusion unstable premixed hydrogen flame combustion.

The present invention discloses a visualization test device and method for accurately testing the effect of a non-steady-state detonation flame arrester for combustible gas, including a vacuum system, an automatic gas distribution system, a schlieren camera system, a non-steady-state detonation blocking test combustion pipeline, a test and data acquisition system, and a high-voltage ignition and synchronization control system. The present invention adopts a method combining high-speed camera technology and schlieren optical technology to shoot and record the process of deflagration to detonation and the flame arrester blocking process in the pipeline, realizes the visualization of the whole process of non-steady-state detonation generation and blocking, and accurately and intuitively presents the dynamic change law of the shape and position of the flame and detonation wave over time. The dynamic rising characteristics of the pressure in the pipeline are measured by a pressure sensor, and the relationship between the pressure in the pipeline and the characteristics of the flame and detonation wave can be analyzed in combination with high-speed schlieren images. The changes in light intensity in the pipeline are detected by a photodiode, so as to obtain the position changes of the initial flame and the later detonation wave, and the propagation speed of the flame and the detonation wave at each moment can be calculated in combination with high-speed schlieren image analysis.

The application discloses a vortex wave flow resistance fire resistance performance test experimental device and method, and the device comprises a visual square explosion pipeline, a vortex wave impedance type attenuation cavity system, a fire resistance system, an adjustable high-pressure ignition system, a high-frequency response explosion suppression system, a high-precision gas distribution system and a multi-parameter acquisition system. The device can realize visual research on the deflagration-to-detonation transition of non-uniform concentration gradient hydrogen, control the flame propagation speed and shock wave intensity entering the attenuation cavity, optimize the structure parameters of the attenuation cavity and establish an explosion parameter theoretical attenuation model. Through the change rule of the explosion resistance characteristics of the fire resistance device under multiple parameters, a quantitative relationship between the shock wave, flame propagation attenuation and the structure parameters of the fire resistance device is established, and quantitative analysis is conducted on the explosion resistance performance of the fire resistance device, the attenuation efficiency of the attenuation cavity and the quenching mechanism. The application fills the technical gaps in the deflagration-to-detonation transition mechanism of hydrogen under non-uniform concentration gradient, the flame and shock wave coupling attenuation mechanism and the quantitative characterization of the fire resistance device with multiple structure parameters.

The invention discloses a rotary detonation engine oil injection strategy control method which comprises the following steps: acquiring a pressure signal and a temperature signal of an annular combustion chamber of a rotary detonation engine, and carrying out working condition division on an engine operation state: under a stable detonation working condition, linearly adjusting the oil injection quantity to an optimal detonation wave working interval; and under the unstable detonation working condition, the fuel injection quantity is adjusted based on the ratio of the detonation wave propagation speed to the detonation wave theoretical propagation speed, an oxidizing agent is injected according to the oxidizing agent flow determined by the optimal fuel injection quantity and oxidizing agent flow ratio till the engine reaches the stable detonation working condition, or the fuel injection quantity and the oxidizing agent flow are linearly adjusted for multiple times. The invention further discloses a corresponding control device and a computer storage medium. It is guaranteed that the engine has stable detonation combustion performance, the unstable oscillation phenomenon of detonation waves is restrained, and the combustion efficiency of the rotary detonation engine is improved.

The invention discloses an iron powder particle cloud combustion numerical calculation method for simulating and considering differential diffusion, and belongs to the field of iron powder combustion numerical simulation calculation. According to the method, numerical simulation can be carried out on 2D flames of iron powder particle cloud free propagation considering differential diffusion under the microgravity condition, and for the difference of thermal diffusivity between gas phase components, the effect of surface reaction kinetics and the effect of a diffusion control mechanism are considered at the same time in an autonomously established iron powder particle combustion model; the local Lewis number is calculated in real time, a diffusion term is corrected in a gas phase component equation, and the influence of differential diffusion on the flame temperature and flame propagation speed of iron powder particle cloud and the influence on the heat release rate of single particle combustion and the mass fraction of oxygen on the particle surface are quantitatively analyzed. The influence of oxygen concentration and thermal expansion on combustion of the iron powder particle cloud is further considered. The method has guiding significance for developing a lean fuel iron flame model with a low flame propagation speed and other metal particle combustion models.

A flame suppressor (10) for venting pipelines, vessels or tanks containing a combustible gas includes a quench module (14) and an injector (16) located in a flow path of the vented pipeline product exiting the quench module (14). The injector (16) introduces an educted jet of a second gas into the flow path so that vented pipeline product has speed above a flame propagation speed of the combustible gas. The second gas may be a non-combustible or inert gas or air and may be used to dilute, as well as accelerate, the vented pipeline product. Or the second gas may inject a combustible gas, for example, methane, still accelerating the vented pipeline product.

The application discloses a numerical calculation method for simulating iron powder particle cloud combustion considering differential diffusion, and belongs to the field of iron powder combustion numerical simulation calculation. The application can numerically simulate 2D free propagation of a flame of an iron powder particle cloud under microgravity conditions considering differential diffusion. For the difference of thermal diffusion rates among gas phase components, the application considers the effects of surface reaction kinetics and diffusion control mechanism in the self-established iron powder particle combustion model, calculates a local Lewis number in real time, corrects a diffusion term in a gas phase component equation, quantitatively analyzes the effects of differential diffusion on the flame temperature and flame propagation speed of the iron powder particle cloud, and the effects of differential diffusion on the heat release rate of single particle combustion and the oxygen mass fraction of a particle surface, and further considers the effects of oxygen concentration and thermal expansion on the iron powder particle cloud combustion. The application has guiding significance for developing a lean fuel iron flame model with low flame propagation speed and other metal particle combustion models.

A prescribed characteristic value (for example, ultrasonic propagation speed) of a fuel in use detected at any position (fuel tank 80) of a fuel supply system is acquired (S3) as a fuel characteristic value Y, and is compared (S5) with a fuel characteristic reference range (Ymin-Ymax), which is a range of a normal value of the characteristic value (ultrasonic propagation speed) of the fuel for use stored in advance in a storage means 21. As a result of the comparison, when the fuel characteristic value Y is out of range (Y < Ymin or Y > Ymax) of the fuel characteristic reference range (Ymin-Ymax) of the fuel for use (NO in S6), it is determined (S9) that fuel abnormality such as mixing of different types of fuel or deterioration with time has occurred in the fuel in use in an engine-driven work machine, a warning notification is issued (S10), and the operation of the engine is limited (S11).