在我国,能源的主要来源是煤,沸腾燃烧锅炉能较好地燃用劣质煤,并将在我国动力工业中迅速得到发展.临界速度u_(mf),的计算在沸腾燃烧锅炉的设计中是很重要的.但是,目前国内外发表的u_(mf)计算公式,在同样的床料特性下,应用不同公式计算时其结果相差甚大.本文针对这个问题在一个常压沸腾床气模试验台上进行了试验研究工作,通过试验,论证了各计算公式在不同范围内的适用性,并建议采用最满意的计算公式C.Y.Wen和公式.但是,当采用小颗粒占少数的双组分物料或混合物料时,建议按下式计算平均粒径: In our country, the main source of energy is coal, and the boiled combustion boiler can burn low quality coal well, which will be rapidly developed in China’s power industry. The calculation of the critical speed u mf is in the design of the boiled combustion boiler However, at present, the u_ (mf) formulas published at home and abroad have different results when using different formulas under the same bedding material properties.In this paper, On the experimental work carried out through the test demonstrated that the calculation formula in different ranges of applicability and suggested the most satisfactory calculation formula CYWen and formula.However, when the use of small particles accounted for a small number of two-component materials or When mixing materials, it is recommended to calculate the average particle size as follows: