采用旋流拱顶燃烧器的W型锅炉炉内流动特性

采用旋流燃烧器，可以强化燃烧器出口煤粉气流的着火，配合采用燃烧器内部分级燃烧方式后，也有利于降低污染气体的排放。但采用旋流燃烧器后，由于W型锅炉燃烧的特殊性，给锅炉的设计和运行带来了新的情况，如对旋流燃烧器在W型锅炉拱顶采用旋流燃烧器后炉内的空气动力特性不能很好得到掌握，不但得不到旋流燃烧器所带来的优点，还会引起很多问题。本文对采用旋流燃烧器的W型锅炉的炉内多相流动特性进行分析，并与相应的采用直流燃烧器的W型锅炉进行对比，指出在采用直流燃烧器的W型锅炉设计中常采用的参数在采用旋流燃烧器时可能会出现的问题，并提出了改进的方法。

In-furnace Aerodynamic Flow Characteristics of a W-shaped Boiler with an Arch-crown Installed Swirl Burner

The use of a swirl burner can contribute to intensifying the ignition of pulverized coal stream at the burner outlet, and coupled with a graded combustion mode within the burner it also leads to a reduction of polluting gas emissions. However, due to the specificity of combustion in a W shaped boiler the adoption of the swirl burner can bring about some new features to the design and operation of the boiler. For example, it may prove difficult to cope with the in furnace aerodynamic characteristics resulting from the use of a swirl burner on the arch crown of the W shaped boiler. In such a case one will not only be deprived of the advantages attributed to the use of the swirl burner but also suffer from a multitude of troublesome issues. In the present paper an analysis is given of the in furnace multi phase flow characteristics of the W shaped boiler equipped with a swirl burner, which have been compared with those of the same boiler using a direct jet burner. Some problems associated with the use of a swirl burner have been pinpointed, which may emerge because of the parameters commonly used in the design of a W shaped boiler fitted with a direct jet burner. In this connection, the authors have proposed a viable method aimed at achieving the desired improvement.