Research On Industrial Waste Heat Utilization Technology Based On The Biomass Supplement Firing

In order to fully recycle low grade industrial waste heat and use biomass energy effectively.A new industry waste heat power generation system with biomass afterburning is proposed.Low temperature waste heat from cement kiln all used to heat water to produce saturated steam,saturated steam is overheated in biomass supplemental combustion system,and then sent to steam turbine.Supplemental fuel is biomass gasification gas.The boiler for complemental burning is a superheater boiler.Based on the waste heat data of 5000t/d cement production line,single and dual pressure waste heat power generation system with biomass afterburning is established,thermodynamic performance is analyzed.The results indicate that cycle thermal efficiency and power efficiency of single pressure system are 1.63 and 1.92 percentage points higher than traditional pure low temperature power generation system.And cycle thermal efficiency and power efficiency of dual pressure system are 1.05 and 1.53 percentage points higher than traditional pure low temperature power generation system.Biomass consumption of single and dual pressure system are 2.95t/h and 1.92t/h.Biomass afterburning input energy to total input energy ratio are 15.23% and 10.5%.The waste heat is the main part.In this paper,waste heat power generation system with biomass afterburning is designed,and the structure parameters of boiler in the system is designed.Because of the superheater is independent from the waste heat boiler,all waste heat of flue gas is used to produce saturated steam.The waste heat power generation system with biomass afterburning produce more steam than traditional pure low temperature power generation system.The influence of the waste heat power generation system with biomass afterburning performance by changing evaporating pressure and pinch point temperature difference is analyzed.The results indicate that,under the same evaporation pressure,as the pinch point temperature difference of single pressure system increases,the system power is reduced,cycle efficiency is unchanged,system efficiency is reduced,biomass consumption is reduced.When the evaporating pressure is 2MPa,pinch point temperature rise from 10? to 20?,the system power is reduced by 8.55%,system efficiency is reduced by 7.46%,biomass consumption is reduced by 8.45%.Under the same pinch point temperature difference,with the increase of the evaporation pressure,the system power is reduced,biomass consumption is reduced,the system efficiency is reduced,but the cycle efficiency increases.When the pinch point temperature difference is 15?,evaporation pressure rise from 1.4MPa to 3MPa,the system power is reduced by 14.8%,cycle efficiency is increased by 10.21%,system efficiency is reduced by 11.53%,biomass consumption is reduced by 23.59%.As for dual pressure system,the change rule is basically same with the single pressure system.But under the same evaporation pressure,with the increase of the pinch point temperature difference,cycle thermal efficiency is gradually reduced.