The strategy to stabilize distributed combustion regimes adopting cyclonic flow fields has been proven to be challenging. In fact, the establishment of a toroidal flow field within a combustion chamber may ensure the recirculation of mass and sensible enthalpy required to simultaneously dilute the fresh reactants and increase the temperature above the autoignition one. The combination of reactants dilution and preheating may greatly increase system energy efficiency and lower pollutants production producing very peculiar combustion regime (named MILD Combustion). At the same time this strategy can be compromised if the sensible enthalpy is not high enough to promote the auto-ignition process of diluted mixtures. This may happen either because of an inefficient recirculation system or due to a too low calorific fuel. The paper aims at exploiting the performance of a small-size cyclonic burner for a conventional fuel (CH₄) and a low calorific fuel (synthetic biogas) through the characterization of the process stabilization and pollutant emissions as a function of the mixture equivalence ratio and the nominal thermal power of the inlet mixture (from 2 to 10 kW), with the aim of identifying the optimal operating condition of the system. Results suggest that the system has to be exercised with mixtures with compositions slightly under the stoichiometric conditions and in a well identified temperature range to minimize both NO_x and CO emission. The burner can be easily exercised also with low calorific fuels for higher thermal powers according to the low LHV. However, it results that an efficient recirculation of the exhausts produces a robust MILD combustion condition also when low calorific fuels are used.

事实证明，采用旋风流场来稳定分布式燃烧状态的策略具有挑战性。实际上，在燃烧室内建立环形流场可以确保同时稀释新鲜反应物并使温度升高至自燃温度以上所需的质量和显热焓的再循环。反应物稀释和预热相结合可以大大提高系统能效，降低污染物产生，产生非常特殊的燃烧状态（称为轻度燃烧）。同时，如果明智的焓值不足以促进稀释混合物的自燃过程，则可能会损害该策略。这可能是由于再循环系统效率低下或热量过低导致的。₄）和低热量的燃料（合成沼气），其特征在于过程稳定度和污染物排放随混合物当量比和入口混合物标称热功率（2至10 kW）的变化而变化，目的是确定系统的最佳运行状况。结果表明，该系统具有到与略低于化学计量的条件和在井识别的温度范围这两个NO最小化的组合物的混合物来行使_X和CO排放。根据低LHV，燃烧器还可以轻松地使用低热量的燃料来获得更高的火力。然而，结果是，当使用低热量燃料时，排气的有效再循环也产生了稳健的MILD燃烧条件。