中文摘要：

从目前立式燃油锅炉的发展现状出发，针对某小型立式燃油锅炉热效率不高，NOx排放偏高的缺点，提出了相应改造方案，建立传热模型分析改造前后炉内燃烧与传热过程，并通过实验进行相关测试研究。经过分析和实验，结果表明：通过在炉膛中加装内炉胆，强化了燃烧与传热过程，提高了热效率，并改善了烟气排放；改造后的燃油锅炉炉膛温度分布均匀，无明显高温区，过量空气系数由1．10降低至1．05以下，NOx排放降低25％以上，排烟温度明显降低，热效率提高2个百分点左右，以上均证明了该改造方案的可行性。

英文摘要：

This paper briefly describes the current status of the development of vertical oil-fired boiler. Then a transform program was proposed in a small vertical oil-fired boiler which with low efficiency and high NOx emissions. We established the heat transfer model to analyze the combustion and heat transfer process before and after the change, moreover, carried out relevant studies through experiments. The analysis and experimental results show that： after installing internal furnace gall in the boiler furnace, combustion and heat transfer process had been enhanced, thermal efficiency improved and harmful emissions reduced, flue gas emissions have been improved. Temperature distribution of oil-fired boiler furnace was uniform, no obvious high-temperature shown; Excess air ratio from 1.10 to 1.05 below, NOx emissions reduced by 25%, and exhaust gas temperature reduced significantly, the thermal efficiency increased about 2 percentage points. All above showed the feasibility of this transformation.