Abstract: Heat-conducting oil furnace is a widely used heating equipment in industry. The performance of heat-conducting oil furnaces is affected by different heat loads during the production process. To investigate the operational flexibility of a thermal oil furnace with a designed load of 25 MW and optimize its operating conditions, numerical simulations of the heat-conducting oil furnace are conducted using computational fluid dynamics under five different heat load conditions (30%, 60%, 80%, 100%, and 110%). In order to obtain a more detailed understanding of the flow and combustion characteristics of the heat-conducting oil furnace, the influence of different heat load conditions on the distribution of parameters such as velocity, temperature, and component concentration during the flow and combustion process inside the furnace are studied and analyzed. The current layout of the burner results in a high velocity difference between the high-speed fuel jet and the air, and there are clear boundaries in the area affected by the jet. The suction effect on the surrounding flue gas is significant near the burner. When the heat load exceeds 60%, the reflux area in the furnace is larger, the residence time of flue gas is prolonged, and the overall temperature in the furnace is higher, which is conducive to the heat absorption and temperature rise of the heat transfer oil in the furnace tube. Under full load and overload operation conditions, it is important to pay attention to the impact of higher flue gas flow rate and temperature on furnace tubes and other components and avoid problems such as convection chamber furnace tube vibration, local overheating, and even overheating caused by high workload. The above research results can provide theoretical guidance for the design and the operation of heat-conducting oil furnaces, which has practical significance.

Key words: heat-conducting oil furnace, heat load, combustion characteristics, numerical simulation

摘要： 工业上应用的导热油炉具有较大的炉膛尺寸和较高的热负荷。对某设计负荷为25 MW的导热油炉进行了三维数值模拟，研究了不同热负荷的工况下炉内流动与燃烧过程中的烟气速度、温度、组分浓度等关键参数的分布规律。结果表明，燃烧器的布置方式使得燃料射流与空气射流间存在较高的速度差，射流卷吸作用明显，炉膛内的温度分布均匀性有待提高。当热负荷超过60%时，炉膛内的回流区域较大，烟气停留时间延长，有利于炉管内导热油吸热升温，但从辐射室进入对流室的烟气流速较大、温度较高。在满负荷和超负荷运行条件下，需控制烟气流速，保持平稳操作。以上研究结果可为导热油炉的设计和实际运行提供理论指导。

关键词: 导热油炉, 热负荷, 燃烧特性, 数值模拟