In order to carry out energy-saving analysis for biomass-coal co-combustion system and provide the theoretical basis

based on thermodynamic law

this paper analyzes the co-combustion system of biomass and coal in a 396 t/h high temperature and high pressure circulating fluidized bed boiler

and studies the influence of biomass blending ratio on exhaust temperature

thermal efficiency and exergy efficiency of the boiler. The results show that

with the increase of biomass blending ratio

the exhaust temperature of the boiler increases gradually

the thermal efficiency decreases gradually from 89.62%

the exergy efficiency decreases gradually from 46.11%

and the heat transfer efficiency of the heating surface inside the furnace and in the tail flue is as high as 98%

while the heat transfer exergy efficiency of the heating surface inside the furnace is only about 38%. Therefore

in the case of exergy analysis

there is still a great potential for energy saving in the furnace.