Figure 9.5 shows the relationship between mean solar collector temperature and
the energy conversion efficiency of solar thermal power generation in KCS-11 using
a vacuum single tube with flat absorber. Energy conversion efficiency increases with
increasing mean solar collector temperature when solar irradiance is greater than
300 W/m
2 and decreases when solar irradiance is less than 300 W/m
2 . Energy
Fig. 9.2 Relationship between solar irradiance and solar collector efficiency when t 0 ¼ 20
C and
t sc ¼ 70
C
Fig. 9.3 Relationship between solar irradiance and solar collector efficiency when t 0 ¼ 20
C and
t sc ¼ 80
C
176
B. Jia et al.