In simulating CFB risers, Yang et al. (2003, 2004) and Lu et al.
(2009) compared the experimental and predicted solid fluxes to
determine whether or not the drag correlations overestimated the
interaction between gas and solid phases. In this work, the effect
of specularity coefficient ϕ on entrained solid flux was also investigated, as shown in Table 6, for different specularity coefficients for
both the Gidaspow drag model and the EMMS-based drag model.
The outlet solid flux decreases with decreasing specularity coefficient, that is, when the specularity coefficient is small, the reduced
slip of particles on the wall leads to more particles flowing downward, and consequently fewer particles are entrained out of the riser by the gas, resulting in the decrease of outlet solid flux. However, all solid fluxes obtained from the Gidaspow drag model are
much higher than the experimental value (14.3 kg/(m
2
s)), owing
to overestimation of the drag coefficient (Yang et al., 2004). The
EMMS-based drag model, however, predicted much closer solid
fluxes to measured data, with a deviation of within 14%.
Fig. 2 shows the axial voidage profiles for different s
ในการจำลอง cfb risers หยาง et al . ( 2003 , 2004 ) และ Lu et al .
( 2009 ) เทียบกับการทดลองและคาดการณ์ค่าแข็ง
พิจารณาหรือไม่ลากความสัมพันธ์ overestimated
ปฏิสัมพันธ์ระหว่างแก๊สและขั้นตอนที่เป็นของแข็ง ในงานนี้ ผลของค่า
specularity ϕบน entrained แข็งไหลมีลักษณะดังแสดงใน ตารางที่ 6 for different specularity coefficients for
both the Gidaspow drag model and the EMMS-based drag model.
The outlet solid flux decreases with decreasing specularity coefficient, that is, when the specularity coefficient is small, the reduced
slip of particles on the wall leads to more particles flowing downward, and consequently fewer particles are entrained out of the riser by the gas, resulting in the decrease of outlet solid flux. However, all solid fluxes obtained from the Gidaspow drag model are
much higher than the experimental value (14.3 kg/(m
2
s)), owing
to overestimation of the drag coefficient (Yang et al., 2004). The
EMMS-based drag model, however, predicted much closer solid
fluxes to measured data, with a deviation of within 14%.
Fig. 2 shows the axial voidage profiles for different s
การแปล กรุณารอสักครู่..