Determining basic characteristics of stabilizer micro torch burners for the combustion of ballasted fuel gases

This paper reports an experimental study into the combustion of alternative gases in the form of a mixture of propane-butane with air and carbon dioxide after a stabilizing flat module whose both sides are flown around with an airflow. The ballasted fuel was fed by jets into the airflow from the holes located on the side walls of the stabilizer. In this case, the fuel and air were partially premixed. It was established that when ballasting fuel with inert admixtures, the length of the torch and the maximum temperature gradually decreased while nitrogen oxide emissions decreased. With an increase in the content of ballast in fuel, combustion breaks. The dependence of torch stability on the relative consumption of ballast has been established. To stabilize the combustion, highly reactive fuel is supplied to the recirculation zone after a stabilizer from a separate collector. Ballasted fuel passes through the next torches of high-temperature fuel; the all fuel combustion process takes place. The combined scheme of mixture formation makes it possible to adjust fuel consumption in the zones and thus maintain a stable burner power. In the case of supplying all fuel to the recirculation zone after the stabilizer, a so-called "rich" detachment is possible when the torch is detached from the stabilizer. When working under such modes, highly reactive fuel is supplied from the holes on the side walls of the stabilizer, which are placed closer to its detachment edges than the holes for the supply of ballasted fuel. At the same time, the jets of ballasted fuel also pass between the torches of highly reactive fuel so there is joint combustion of all fuel

Scaling Methodology of the FAA Burner for Pre-Qualification Fire Tests of Aircraft Engine Panels

The main objective of this work is to design a small kerosene burner to study the fireproofing capacity of aircraft composite materials exposed to an open flame. The standards AC20-135 and ISO-2685 describe how the fireproofing tests have to be performed and serve as guidelines to set the requirements for the design of a small kerosene burner as a less costly alternative to the larger FAA burner. The burner is fed with liquid jet-A fuel and air, which is flowing around the injector in a cylindrical chamber. The combustion generates an unconfined flame. The fuel injector selected is a Delavan spill-return pressure atomizer. There is a custom 3D printed plastic axial swirler at the inlet of the combustion area to promote better mixing between air and jet-A droplets. A computational fluid dynamic analysis (CFD) is presented to better understand the aerodynamic of the burner and to design adequately the swirler. The design of the burner allows changing easily the swirler to test swirlers with different vane angles. An experimental test bench is designed to test the effect of these swirlers on the heat flux measurements under multiple combinations of burner power and equivalence ratio at four axial locations. The experimental investigation allows selecting the final configuration and parameters for the burner. The chosen swirler has 15 vanes that are oriented at the exit at 25° to the burner axis. The best axial location for the measurements from the burner face to the position of the calorimeter is at 7.6 cm (3 in.). It is possible to generate a flame with a diameter smaller than 6.4 cm (2.5 in.) while reaching the required heat flux of 116 kW/m2. This accommodates smaller coupon sizes for the composite material and reduces cost for pre-certification FAA testing. To achieve this flame configuration, the burner power should be set between 10 kW and 20 kW with an equivalence ratio from 0.7 to 0.9.

MODERNIZATION OF GAS BOILERS OF TPP, CHP AND BOILERS ROOMS TO THE EU DIRECTIVE ECOLOGICAL REQUIREMENTS

The installed capacity of boiler units in Ukraine significantly exceeds the needs for consumers was shown. The remarking of boiler units to lower capacity is the one of the least capital-intensive ways to increase their technical, economic, environmental indicators and the extension of their resource. To achieve EU norms it is necessary to reduce emissions of NOx by 50–80 % for boilers of LCP with an capacity a rated thermal input of 50 MW or more, which operate on natural gas has been established. An increase the concentration of recirculation gases in blow air of more than 25 % of all exhaust gases significantly reduces the concentration of oxygen in the mixture of air and exhaust gases. It’s can cause to: deterioration of combustion, the removal of a torch into the convective part, a significant increase electricity consumption and increase the temperature of the exhaust gases. The using of CO2 or N2 gases for balancing natural gas to reduce NOx emissions is economically impractical. The using of ballasting technology, which based on mixing exhaust gases with natural gas, requires special burners, due to the range of burner power control must be limited. To reduce NOx is advisable to combine several measures simultaneously. The plan an action to implement EU environmental directives by existing boiler units operating on natural gas with an increase their technical and economic indicators has been developed. There is one of the possible ways to implement the EU ecological directives by boiler units in Ukraine, it’s transferring the load from existing LCP with a rated thermal input of 50 MW or more to less powerful ones. For remove combustion plants from the requirements of the EU Directive 2010/75/EU, it is necessary to remark part of the boilers for a new nominal capacity for the purpose of obtaining combustion plants a rated thermal input of less than 50 MW. Bibl. 18, Fig. 6, Tab. 1.