烟气与液体介质直接换热技术研究及应用

Study and Application of Direct Heat Transfer Technology between Flue Gas and Liquid Medium

为了提高油田加热炉换热效率,本文对高温烟气与低温液体直接换热的机理进行了研究,两种物质之间的换热以对流换热为主、热传导为辅,换热系数主要取决于两种物质的相对速度,换热面主要取决于液体的表面积。在机理研究工作的基础上,对烟气与液体介质直接换热式油田加热炉结构进行了研究,燃料和空气在炉膛内充分混合燃烧,产生的高温烟气温度分布均匀后进入换热室把热量传递给低温液体,低温液体以喷淋的形式进入换热室,被加热后的液体受重力作用落入缓冲室缓冲后离开加热炉。最后,对烟气与液体介质直接换热式油田加热炉样机进行了设计、加工、安装、调试以及现场试验,样机炉体比同负荷现有负压加热炉节约钢材63%以上,热效率较常规加热炉提高了10个百分点,超过90%。

In this paper,the mechanism of direct heat transfer between high-temperature flue gas and low-temperature liquid is studied.The heat transfer between the two substances is dominated by convection and supplemented by heat conduction.The heat transfer coefficient mainly depends on the relative velocity of the two substances and the heat transfer surface mainly depends on the surface area of the liquid.In the mechanism research,on the basis of direct heat transfer of flue gas and liquid medium type oil field heating furnace structure are studied,fully mixing fuel and air in the chamber of a stove or furnace combustion,the temperature of the high-temperature flue gas produced evenly distribution of heat transfer into the heat exchange chamber for cryogenic liquid,cryogenic liquid in the form of a spray into the heat exchange chamber,after heated liquid by gravity into the buffer rooms after leaving furnace.Finally,the design,processing,installation,commissioning and field test of the prototype oil-field heating furnace with direct heat transfer between flue gas and liquid medium are carried out.