YANG Xiujuan, YAN Weiping. Study on the process of the flue gas fluidized lignite drying and unsteady heat and mass transfer[J]. Thermal power generation, 2018, 47(4): 1-8.
DOI:
YANG Xiujuan, YAN Weiping. Study on the process of the flue gas fluidized lignite drying and unsteady heat and mass transfer[J]. Thermal power generation, 2018, 47(4): 1-8. DOI: 10.19666/j.rlfd.201706044.
Study on the process of the flue gas fluidized lignite drying and unsteady heat and mass transfer
In order to reflect the actual drying process of lignite particles and provide reference for design parameters of fluidized bed gas drying lignite system
this study establishes an unsteady drying and temperature rising model of lignite particles under fluidization state based on the unsteady boundary conditions.Using the Runge-Kutta
the differential equations describing the drying process of lignite particle are simulated and calculated.And then the change rules of moisture content
temperature and flue gas temperature with time during the lignite drying process are obtained.The results show that when the gas initial temperature is 260
200 or 140 ℃
the drying rate is 0.076
0.068 or 0.054 kg/min
respectively.When the particle size is 1
3
5 or 7 mm
the drying rate is respectively 0.074
0.068
0.065 or 0.062 kg/min.When the gas flow rate is 2.8
2.5 or 2.0 m/s
the drying rate is respectively 0.068
0.074 or 0.076 kg/min.When the bed thickness is 120
200 or 300 mm
the drying rate is respectively 0.076
0.073 or 0.068 kg/min
and the recommended drying time is 3~4 min
4~5 min or 5~6 min
respectively.The optimal target moisture content of lignite is about 10% and the suitable drying temperature is 140~260 ℃.