10 results about "Propagation rate" patented technology

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.

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 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 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 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 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.

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.