水蒸气载热式锅炉烟气余热回收系统的节能量测量方法
Energy saving measurement method for flue gas waste heat recovery system with a water vapor heat carrier boiler
摘要：
烟气余热回收可有效降低锅炉的排烟热损失,减少燃料耗量和温室气体排放。近年来,作为一种高效的全热热回收方式,水蒸气载热式锅炉烟气余热回收系统已在实际工程中得到一定的应用,但由于其流程及能量转化关系较为复杂,人们对该系统节能量如何判定存在争议。本文在分析烟气余热回收系统及其各环节的能量平衡与转化关系基础上,提出了采用温度传感器、热计量表等常规仪表间接测量整个余热回收系统及其锅炉助燃风预热节能量的方法,并以山东临邑恒利热电厂为例给出了采用水蒸气载热式锅炉烟气余热回收前、后的测量结果。数据分析表明,对于蒸发量为176.90 t/h的锅炉,整个烟气余热回收系统的总节能量为10.86 MW,占锅炉产热量的8.46%,其中通过锅炉的进风预热加湿使锅炉加热助燃风节能1.73 MW,占余热总回收量的16%。该测量方法为水蒸气载热式锅炉烟气余热回收系统规模化应用提供了节能量在线实时监测的技术支撑。
Abstract：
Flue gas waste heat recovery can effectively reduce the exhaust heat loss of boilers, decrease fuel consumption, and lower greenhouse gas emissions. As an energy-efficient heat recovery system for both sensible and latent heat, the heat recovery system with spraying water in flue gas and humidification in inlet air of boilers has been used in many projects recently. However, there are arguments on how to evaluate the energy-saving rate of the system because of the complex process and energy conversion relationship of the system. Based on the analysis of the energy balance and conversion relationships in the flue gas heat recovery system, a method for calculating the energy savings of the whole system compared with the system without flue gas heat recovery, including inlet air preheating in boilers, is proposed by using conventional equipment such as temperature sensors and heat meters. Taking the Hengli Thermal Power Plant in Linyi County, Shandong Province as an example, measurement and energy saving results after the implementation of flue gas waste heat recovery system are provided. The results reveal that for a boiler with an evaporation rate of 176.90 t/h, the total energy savings achieved by the entire flue gas heat recovery system amount to 10.86 MW, which accounts for 8.46% of the heat output of the boiler. Among these savings, 1.73 MW is obtained through boiler inlet air preheating and humidification, constituting 16% of the total heat recovery. This measurement method provides technical support for the real-time online monitoring of energy savings in the large-scale implementation of the system.
Keywords:boiler; flue gas waste heat recovery; sensible and latent heat recovery; inlet air humidification; indirect method of measurement