【摘要】 以陕北天然气为例,在对锅炉各项热损失进行分析的基础上,给出了不同排烟温度下,水蒸气汽化潜热在锅炉排烟热损失中所占的份额大小。并指出,若采取措施将烟气中的潜热加以回收利用,可大幅度提高锅炉的热效率。对于陕北天然气,如果排烟温度降到40℃,烟气中水蒸气汽化潜热的70%可得到回收,锅炉热效率将比排烟温度为180℃~250℃的传统锅炉提高13.5%~16.6%。冷凝式锅炉的热效率提高潜力主要取决于燃料种类、锅炉本体的排烟温度、工艺流体的温度、所需的低品位热能的数量、过量空气系数等。更多还原

【Abstract】 Based on an analysis of the heat losses of a Shanbei natural-gas-fired boiler, the latent heat of the water vapor contained in the flue gas is quantitatively characterized at different exit flue-gas temperatures. It is concluded that the thermal efficiency of the boiler can be substantially increased if the latent heat locked in the flue gas is recovered. When the exit flue-gas temperature is reduced to 40℃, 70% of the latent heat of the water vapor in the flue gas can be recovered for a Shanbei natural-gas-fired boiler, and the thermal efficiency can be increased by 13.5%~16.6% compared to conventional boilers with an exit flue-gas temperature of 180℃~250℃. The potential for efficiency improvement depends mainly on the fuel type fired, the exit flue-gas temperature, the process fluid temperature, the low-level heat required, and the excess air etc.更多还原