Utilization And Energy Saving Analysis Of Condensation Waste-heat Of Natural Gas Boiler

With the development of China's industrialization and the upgrading of consumption structure,energy consumption gap is increasingly serious and energy import dependency leads to the severe energy security situation.Besides,unreasonable energy structure has caused serious environmental problems.Accordingly,energy saving and emission reduction has become a long-term strategy for China's economic construction and social development.Natural gas is a kind of clean energy,which has the characteristics of high quality,high efficiency and low pollution,the efficient use of natural gas has important significance for improving energy efficiency and environmental protection.The gas boiler exhaust gas temperature more than 150 ?,so the latent heat of vaporization contained in water vapour has not been utilized,and the loss rate exceeds 10%.If the flue gas temperature is reduced below dew point temperature,the boiler efficiency will be greatly improved and will bring energy saving and economic benefits.This paper targeted condensation waste-heat utilization and energy saving analysis of natural gas boiler,analyzes the gas condensing boiler waste heat utilization principle and technology.Using theoretical calculation,analysis the combustion characteristics of natural gas,the thermal efficiency,condensing characteristics and energy saving potential,provide theoretical support for the suggestion on the optimization using condensation heat.This paper demonstrates the exhaust gas temperature,excess air ratio,heating system and air humidity ratio influence on the heat loss of exhaust gas.The research shows that exhaust heat loss is reduced along with the decrease of exhaust gas temperature,the inflection point appears at the dew point temperature and change sharply below dew point temperature.Besides,excess air ratio and heat loss of exhaust gas is positive correlation,and the air humidity ratio and dew point temperature is the same rule.The heat loss of flue gas increases with the increase of air humidity ratio.This paper selects a waste heat recovery project in a boiler room as an example.Based on the theoretical calculation and operation data,two aspects of energy saving and economy are analyzed.The existing reform plan uses the recovered heat for increase the backwater temperature of primary pipe network.The flue gas temperature is reduced about 40?,the water temperature is increased about 15?,The average recovery of the waste heat recovery unit is 1.9%,and the project recovery period is 2.86 years.The data of heating season show that the heat and benefit are considerable after transformation.Meanwhile,puts forward envisage and suggestion on the maximize the optimal use,provide reference for similar reconstruction project.