一种新型天然气锅炉烟气余热回收系统

引言随着城市生活水平的提高,空气质量逐渐成为人们关注热点,清洁能源得到越来越广泛的应用。天然气的大量开采,使得天然气锅炉凭借其节能环保的优势在城市供暖中逐渐占据主导地位。然而,天然气锅炉同样存在排烟温度高引起的一次能源浪费问题。目前大多数热水锅炉的排烟温度为140~200℃,一些蒸汽锅炉则高达250℃。同时,由于

A novel heat recovery system for flue gas from natural gas boiler

The exhaust flue gas from natural gas boiler(NGB)contains a lot of sensible heat and latent heat,and recycle and utilization of the heat can significantly improve energy efficiency.Based on the heat features of NGB flue gas,a new heat recovery system was proposed to realize recycle and cascade utilization of both latent and sensible heat in the flue gas.In this system,the high grade sensible heat is converted to electric energy by organic Rankine cycle(ORC),while the low grade sensible heat and latent heat recovered by condensation of working fluids and absorption of cooling water.A thermodynamic and economic model is established to evaluate the system performance.The results show that,thermal efficiency of natural gas boiler equipped with the heat recover unit increase by 11% under the reference conditions,and payback period of the unit is about 1.2 years,and the net present value is approximately 4.32 million CNY after five years.Based on this performance evaluation,effects of main operating parameters on system thermodynamic and economic performance are analyzed,which can provide a foundation for optimization of the system.