微油点火燃烧器数值结果精度判断准则与分析

Accuracy criterion and analysis of numerical result for tiny-oil ignition burner

为了提高数值计算精度,必须要有一种判断精度的准则,结合马莲台电厂1号锅炉微油点火燃烧器改造,提出了炉膛内火焰形状相似度对比法。它以数值结果的火焰形状与实际燃烧火焰形状进行对比,计算出二者的相似度,从而量化数值计算结果的精度,该方法已成功应用到微油点火燃烧器改造设计中。根据火焰形状相似度对比法,微油点火燃烧器计算模型选择合理、数值计算精度较高,已能反映出实际点火过程;分析了煤粉与油雾混合气流燃烧、传热的过程,深入掌握了微油点火燃烧器点火时的流场数据和颗粒场数据。

In order to improve numerical precision, a criterion to judge the accuracy is needed. Combining with the retrofit of tiny-oil ignition burner in No. 1 unit of Maliantai plant, the contrast method of flame shape in furnace was presented, which can quantize the accuracy of numerical result by comparing the shapes of the numerical results with the actual flame and calculating tbeir similarity. And this contrast method has applied in tiny-oil ignition burner successfully. According to the method of flame shape similarity comparison, the computational model is reasonable and the accuracy ofresuh is higher. It can reflect the actual ignition process. Finally, numerical simulation on combustion and heat transfer of the mixture of pulverized coal and gasified fuel-oil was analyzed; the data of flow field and particle field in tiny-oil ignition burner was well mastered.