给水预热器及膜式水冷壁对注汽锅炉热效率的影响

Effect of Feedwater Preheater and Membrane Wall on the Thermal Efficiency of Steam-injection Boiler

提出多种注汽锅炉改进方案,包括去除给水预热器、辐射段采用膜式水冷壁和在只具有烟气转向作用的过渡段增设膜式水冷壁。通过热力计算综合对比不同改进方案对注汽锅炉热效率、排烟温度、换热温压及燃料消耗量等重要参数的影响,并确定最佳改进方案。结果表明:去除给水预热器可以大幅提高油田注汽锅炉热效率。辐射段与过渡段采用膜式水冷壁对排烟温度影响较小,但可以有效降低对流段入口烟温,降低对流段管子超温烧毁的几率。

In this paper,a variety of improved schemes for heating surface structure of steam-injection boiler were proposed,including the removal of feed water preheater and the adoption of membrane wall in the radiation section and in the transition section for steering the flue gas respectively.Through the thermodynamic calculation and comparing the effects of various improved schemes on the thermal efficiency of steam-injection boiler,the temperature of exhaust flue gas,the heat transfer temperature differences and the fuel consumption,the best improved scheme was determined.The analysis shows that,removing the feedwater preheater can greatly improve thermal efficiency of the steam-injection boiler;and the influence of adopting membrane water wall in the radiation section and transition section upon the temperature of exhaust flue gas can be negligible,but it can effectively reduce the inlet flue gas temperature at the convection section.