| Coal-fired power plant consume a lot of coal resources while providing electricity in China,boiler as one of the main equipment of the power plant,its efficiency will affect the overall economic performance,reducing the heat loss of the boiler can effectively improve the efficiency,and the heat loss of exhaust gas accounts for the largest proportion of the boiler heat loss,so it is an important energy-saving measures to recover waste heat from flue gas through the heat recovery system.This paper takes Baotou third thermal power plant 2 * 300 MW unit as an example.The unit is matched with the HG-1025/17.5-YM11 boiler produced by Harbin boiler plant,which is a natural circulation,a single furnace,an intermediate reheat,balanced ventilation,four corner tangentially fired boiler.Boiler adopts tight closed-type layout,solid slag,full suspension steel frame structure.The actual operation shows that the average annual exhaust gas temperature of the boiler is about 120?,and the temperature at full load in summer is about 145?.In order to make full use of the waste heat of exhaust gas,a low temperature economizer is added between the air preheater and the dust collector in the first stage,and the flue gas temperature is reduced to 98?.After the transformation of the unit,the air preheater soot blowing appears the phenomenon of ash blocking,the increase of the soot blowing frequency,the loss of the heating surface is obvious.The heater vibration causes serious leakage of heating surface and low utilization rate.In order to solve the above problems,fully tap the potential of the existing low temperature economizer,improve the operating environment of the air preheater,promote energy saving and emission reduction.Baotou third thermal power plant carried out the comprehensive utilization of flue gas waste heat recovery project.The utility model can be used for heating the air heater with the condensed water,and the outlet air temperature of the air heater can be heated to 55? at full load.An air heater body to increase the resistance 378 Pa,the two air heater body to increase the resistance of 400 Pa,the new electricity load of about 114 k W,can reduce the coal consumption of about 1.10g/ k W·h,annual savings of 1809.2 tons of standard coal,the annual coal revenue 427 thousand yuan,a single machine equipment investment is 3.4119 million yuan,the static investment of 3.9783 million yuan,two machine static a total investment of 7.9567 million yuan.In addition to energy saving,the waste heat comprehensive utilization system can also solve the vibration problem of the existing air heater,the temperature of the air inlet of the air preheater can be lowered down after the air temperature of the air preheater is increased,and the utility model is beneficial to play the role of the soot blower. |
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