Experimental study of the influence of ignition source position on the parameters of peat fire propagation

The penetration of smoldering combustion into the peat layer was experimentally studied taking into account a different botanical peat composition typical in the Tomsk region of Russia. The laboratory tests allowed us to obtain and analyze the temperature of the peat samples versus time, and also to estimate the velocity of the smoldering combustion in the horizontal and vertical directions. The results showed the faster penetration of smoldering combustion into the grass-sphagnum peat compared with the pine-cotton peat. The botanical composition and the flow of oxidizers in the combustion zone have a significant effect on the smoldering combustion, especially on the penetration of smoldering front into the peat layer. The chaotic distribution of the fuel particles contributes to the propagation of smoldering combustion both in the horizontal and vertical direction and influences on the spread of the smoldering front

Studying the effect of fire retardant coating on the fire hazard characteristics of wood using infrared thermography

This paper represents a study concerning the effect of fire retardant treatment «FUKAM» on the fire hazard characteristics of pine, aspen and larch. The front of model ground fire was investigated to estimate its effect on the surface of wood samples. Infrared thermography was used as a diagnostic method. The surface temperature distribution was obtained for the test wood samples after exposure to a fire front that was modeled using pine needles. The probability of ignition was estimated for the chosen experimental parameters for each kind of wood. The fire hazard characteristics of wood after fire retardant treatment showed a significant reduction in the surface temperature and the resistance to fire for the chosen parameters of the experiment compared to the same untreated samples

Estimation of the influence of wood-fire retardants on fire behavior of some types of wood construction materials

In this paper the effect of fire front on the surface of wood samples (pine, aspen and larch) was presented to estimate the effect of different wood-fire retardants. Infrared thermography was used as a diagnostic method. Modern methods of IR-diagnostics and the use of thermal imagers eliminate the need for a large number of thermocouples, which perturb the investigated medium during measurements. At the same time, a much better resolution in space and time can be obtained using infrared diagnostics. The surface temperature distribution was obtained for the test wood samples after exposure to a fire front that was modeled using pine needles. The ignition probability was estimated for the chosen experimental parameters for each kind of wood. In the infrared region the sample surface characteristics were recorded using a thermal imager JADE J530SB with a 2.5–2.7 micron optical filter that allowed a temperature to be measured in the range of 500–850 K. In order to record a temperature in the range of 293–550 K, the recording was conducted without a filter. The fire hazard characteristics of wood after fire retardant treatment showed a significant reduction in the surface temperature and the resistance to fire for the chosen parameters of the experiment compared to the same untreated sample

Justification of choice of the spectral range for the study of combustion processes with the use of thermography in the middle IR range

The paper presents the emission spectra of flame formed during combustion of different fuels and gives the grounds for application of various narrow spectral ranges in the mid-infrared region to record the temperature fields in flame and flame screened objects

Investigation of the ignition of wood structural materials (with and without fire retardant treatment) under the influence of a model fire of irregular intensity

In this paper the effect of fire front on the surface of wood samples (plywood and oriented strand board) was considered to estimate the effect of different wood-fire retardants. Infrared thermography was used as a diagnostic method. The ignition probability was estimated for the chosen experimental parameters for each kind of wood The fire hazard characteristics of wood after fire retardant treatment showed a significant reduction in the surface temperature and the resistance to fire for the chosen parameters of the experiment compared to the same untreated samples. The charring depth of the wood samples was determined depending on the type of wood, as well as on the type of the fire retardant used

The effect of pressure pulsation on diffusion combustion

The paper presents the results of a study of diffusion combustion of gasoline in the presence of external pressure pulsations with small amplitude. It is found that external pressure pulsations lead to characteristic changes in the temperature field, which are expressed by an increase in the amplitude of the temperature pulsation for certain modes of pressure pulsations. Analysis of the spectra of temperature changes in the entire recorded area showed an unevendistribution of frequency maxima

Application of thermography in experimental studies of plasma jets

The paper presents the experimental studies of the optical properties for the plasma jet in the mid-IR range

Effect of wood structure geometry during firebrand generation in laboratory scale and semi-field experiments

As the set of experiments result, statistically substantiated data were obtained on the laws of ignition of a model angular structure under conditions of a point source of heat exposure. The use of IR diagnostics made it possible to control the thermal picture in the experimental area, as well as to capture areas of the highest and lowest heating. In the Large Aerosol Chamber of IAO SB RAS, preliminary experiments were carried out on a “firebrand shower” model exposure, which is naturally occurring firebrands (flaming or glowing embers) with some types of construction materials (chipboards). The exposure of the samples to firebrands stream was provided using a firebrand generator of own original design. It was experimentally confirmed that particle size plays a significant role in the ignition of a building structure. If the characteristic particle size, which can be defined as the ratio of its volume to the surface area in contact with the wood, is less than a certain characteristic value, then the ignition mode with a sharp temperature maximum near the phase interface is not fulfilled. This can be explained by the prevailing heat removal into the external environment in comparison with the amount of heat coming from a heat gun and resulting from chemical reactions