Evaluation And Analysis Of Shenyang Quanyuan Boiler House Flue Gas Waste Heat Recovery Retrofit Project

Aiming at the problems of high exhaust gas temperature and low thermal efficiency of boilers in Shenyang,this paper takes No.1 boiler in the spring boiler room of Huitian Company of Shenyang as an example to analyze and evaluate the retrofit project of waste heat recovery from flue gas.Firstly,the heating situation of 15 boilers of 29MW and above in 7 large heat source plants of the company was investigated.The results show that the average coal consumption index of heating is 47 kg/m2,the smoke exhaust temperature range of the tested boiler is 150?300 C,and the thermal efficiency of the boiler is 59%?80%.There is a large space for energy-saving transformation.This paper demonstrates the feasibility of the reconstruction project of waste heat recovery from flue gas from the aspects of national policy,energy saving and environmental protection.Secondly,four boilers in Quanyuan Boiler House were tested.The results show that the exhaust gas temperature of four boilers is around 204 C,which is higher than the rated flue gas temperature of 140 C.There is a large space for waste heat recovery.The heat balance efficiency is about 60%.This shows that the unit consumption of coal increases while meeting the temperature parameters of water supply,resulting in waste of resources.Thirdly,the analysis and test of the retrofitting project of flue gas waste heat recovery showed that the heat loss Q2 of flue gas was significantly reduced,and the average temperature of flue gas was reduced from 204 before retrofitting to 159 after retrofitting,with a decrease of about 50.The average thermal efficiency increased from 62.81%to 71.74%before the retrofit,with an increase of nearly 10%.Finally,the energy-saving,economic and environmental benefits of the renovation project are analyzed.After the renovation,the coal-fired saving rate is about 4.06%,and the electricity consumption saving rate is about 4.33%.After the transformation,the fuel cost was saved by 282750 yuan and the electricity cost was saved by 24,000 yuan.Expected payback period of 7 years.The sensitivity analysis shows that with the increase of electricity price and coal price,the energy saving benefit of this project is higher.SO2 emissions decreased by 7.59%,NOx emissions by 8.03%,CO2 emissions by 5.17%,and soot emissions by 9.68%.By adding flue gas waste heat recovery equipment to the spring source boiler,the thermal efficiency of the boiler has been significantly improved,the concentration of pollutants discharged has been significantly reduced,and the enterprise has achieved the goal of energy saving,emission reduction and operation cost reduction.