68
B. S. Mukesh et al.
single spot on the mirror will actually form an elliptical spot on the target with a
major axis length of d Lovegrove and Pye (2012). The width of the focal spot on the
focal plane is given by Eqs. (5.5) and (5.6)
d =
2P sin θ s
cosφ R
(5.5)
where
P =
0.5W
sinφ R
(5.6)
A parabolic dish of focal length (f ) = 1.5 m, aperture (W ) = 2.4 m and depth of
parabola (Z R ) = 0.24 m has been designed with a collector aperture area of ∼4.6 m
2 .
This gives an input power of ∼2.5 kW. For the calculation of input power an average
irradiance of 641.1 W/m
2 is taken. The sun rays reflected from the parabolic dish is
concentrated onto the receiver. These rays form an elliptical spot. Taking the value
of angular distribution of the solar source (half angle θ s ) as 0.0046 rad, and using
Eq. (5.4), φ R comes out to be 0.76 rad. Now using Eq. (5.5), the width of the focal
spot obtained is 2.25 cm. To increase the width of spot on the receiver, flexibility is
provided in the design for a movement of 5–10 cm along the vertical direction. The
optical model as shown Fig. 5.4 is designed using TracePro software to calculate the
receiver travel so that the width of the spot is 20 cm.
The solar radiation incident on the parabolic dish is reflected on to the receiver
at the focus. This model is used as reference to generate flux density distribution.
Figure 5.5 shows the flux distribution and width size at focal point i.e., receiver is
placed at 1.5 m vertical from the vertex of parabolic dish. To get a spot of width 20 cm,
the receiver is moved down by ∼10 cm. The spot of width 20 cm covering the receiver
Fig. 5.4 Optical model for
ray-tracing
B. S. Mukesh et al.
single spot on the mirror will actually form an elliptical spot on the target with a
major axis length of d Lovegrove and Pye (2012). The width of the focal spot on the
focal plane is given by Eqs. (5.5) and (5.6)
d =
2P sin θ s
cosφ R
(5.5)
where
P =
0.5W
sinφ R
(5.6)
A parabolic dish of focal length (f ) = 1.5 m, aperture (W ) = 2.4 m and depth of
parabola (Z R ) = 0.24 m has been designed with a collector aperture area of ∼4.6 m
2 .
This gives an input power of ∼2.5 kW. For the calculation of input power an average
irradiance of 641.1 W/m
2 is taken. The sun rays reflected from the parabolic dish is
concentrated onto the receiver. These rays form an elliptical spot. Taking the value
of angular distribution of the solar source (half angle θ s ) as 0.0046 rad, and using
Eq. (5.4), φ R comes out to be 0.76 rad. Now using Eq. (5.5), the width of the focal
spot obtained is 2.25 cm. To increase the width of spot on the receiver, flexibility is
provided in the design for a movement of 5–10 cm along the vertical direction. The
optical model as shown Fig. 5.4 is designed using TracePro software to calculate the
receiver travel so that the width of the spot is 20 cm.
The solar radiation incident on the parabolic dish is reflected on to the receiver
at the focus. This model is used as reference to generate flux density distribution.
Figure 5.5 shows the flux distribution and width size at focal point i.e., receiver is
placed at 1.5 m vertical from the vertex of parabolic dish. To get a spot of width 20 cm,
the receiver is moved down by ∼10 cm. The spot of width 20 cm covering the receiver
Fig. 5.4 Optical model for
ray-tracing