The exhausted gas recirculation inside the combustion chamber represents a challenging strategy to stabilize the oxidation process for novel combustion processes that aim at reducing pollutants emission, controlling the system working temperature by diluting the fresh incoming charge, and keep high process efficiency. The mass and sensible enthalpy ratio of recycled exhausted gas represents a key parameter to promote and stabilize the oxidation process.

The chemical/thermodynamic features of the oxidation process were investigated by means of a numerical analysis. The process was schematized as a non-adiabatic constant-volume Continuous-flow Stirred-Tank Reactor (CSTR) where part of the exhausted gas was recirculated back to the reactor. The stability of the process was investigated as a function of the pre-heating temperature and of the dilution level of propane/oxygen/nitrogen mixtures for a fixed recirculation ratio.

Following, experimental tests were realized in a small size burner characterized by a strong internal recirculation ratio, induced by a cyclonic fluid-dynamic pattern obtained by the geometrical configuration of the reactor and of the feeding system. The facility was designed to independently vary the mixture pre-heating temperatures and the mixture dilution levels.

The experimental results suggest that the cyclonic configuration represents a challenging choice to stabilize the oxidation process in small-size applications. It contains the pollutants emission for a large range of preheating temperature – mixture dilution levels extending the burner operability conditions.

燃烧室内的废气再循环代表了一种具有挑战性的战略，该战略旨在稳定新型燃烧过程的氧化过程，以减少污染物排放，通过稀释新鲜进料来控制系统工作温度并保持较高的过程效率。再循环废气的质量和显热焓比是促进和稳定氧化过程的关键参数。

通过数值分析研究了氧化过程的化学/热力学特征。该过程被示意为非绝热恒定体积连续流搅拌釜反应器（CSTR），其中一部分废气再循环回到反应器中。对于固定的再循环比，根据预热温度和丙烷/氧气/氮气混合物的稀释水平的函数研究了工艺的稳定性。

随后，在以强内部循环比为特征的小型燃烧器中进行了实验测试，该内部循环比是由反应器和进料系统的几何构型所获得的气旋流体动力学模式引起的。该设备旨在独立地改变混合物的预热温度和混合物的稀释水平。

实验结果表明，在小型应用中，旋风分离器配置是稳定氧化过程的一项挑战性选择。它包含了在很大范围的预热温度下的污染物排放-混合物稀释水平扩展了燃烧器的可操作性条件。