15
Vacuum
tube collector Unit OKP 10 OKP 20
Number of tubes Pieces 10 20
Gross surface m
2
1.7 3.25
Outer dimensions m 1.995 x 1.995 x
(L x W) 0.852 1.632
Aperture surface m
2
0.94 1.88
Absorber surface m
2
0.81 1.62
Weight kg 42 78
Absortivity coefficient
␣
≥ 0.94 ≥ 0.94
Emissivity coefficient
≤ 0.07 ≤ 0.07
Collectors tilt angle Degree 15 up to 75 15 up to 75
Stagnation temperature
at 1000 W/m
2
and 30°C °C 210 210
Max. permissible
working pressure bar 10 10
Collector heat return kWh/m
2
> 525 > 525
Heat exchanger content l 1.2 2.1
Table 1: Technical data of tube collectors OKP 10 and
OKP 20
Illustr. 30: Dimensions of tube collectors (illustr. OKP 20)
W
L
5 Dimensions and technical data
5.1 Pressure loss chart OKP 20
5.2 K
v
values
Numb. of tubes OKP 10 OKP 20 K
v
, total
10 1 0 3.79
20 0 1 2.89
30 1 1 2.30
40 0 2 2.04
50 1 2 1.80
60 0 3 1.67
70 1 3 1.53
80 0 4 1.45
90 1 4 1.35
100 0 5 1.29
110 1 5 1.22
120 0 6 1.18
P
re
s
s
u
re
l
o
s
s
[
m
b
a
r]
Flow rate [l/min]
Chart 1: Pressure losses
Heat transfer liquid “Tyfocor LS” with 40°C
Pressure loss indications without connection hoses
Table 2: K
v
values
6 OKP 20 in series
5 OKP 20 in series
4 OKP 20 in series
3 OKP 20 in series
2 OKP 20 in series
1 OKP 20 in series
