Vaillant Solar hot water systems, Системное руководство

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Manual - Solar hot water systems 10
4.1.2 VFK 900 flat collector
Fig. 4.6 View of the auroTHERM VFK 900, two modules
Equipment
The Vaillant VFK 900 flat collector includes a seawater-
resistant aluminium frame as well as a copper surface
absorber with selective Cermet Vacuum coating.
The Vaillant VFK 900 flat collector has a CFC-free,
standstill temperature-resistant mineral wool insulation
for long-life, excellent heat insulation.
For easy assembly, all connections were designed as flat
gasket. The sensor sleeve integrated in the middle and
the symmetric interior structure means that the
collector array can be connected variably.
4 Description of the components
Technical data of the flat collector
Appliance designation Unit. auroTHERM VFK 900
Surface area (gross, aperture/net) m 2 2.24/2.02
Height mm 1930
Width mm 1160
Depth mm 110
Weight kg 43
Absorber capacity l 1,1
Copper pipe connection, flat-face Ø mm G 1/2"
Insulation thickness mm 60
Max. operating pressure bar 10
Solar safety glass transmission
τ
(dew) % 90
±
2
Absorber emission
ε
(epsilon)
% 5
±
2
Absorber absorption
α
(alpha)
% 95
±
2
Solar sensor sleeve Ø mm 6
Qualification approval mark CE 0036
Shutdown temperature (according to prEN 12975-2,
c < 1 m/s)
°C 227
Efficiency
η
0
% 81,9
Efficiency coefficient k1 W/(m 2 •K) 3,47
Efficiency coefficient k2 W/(m 2 •K 2 ) 0,0101
Table 4.2 Technical data of the flat collector auroTHERM VFK 900
Fig. 4.7 Efficiency of the auroTHERM VFK 900
acc. to DIN 4757/4
1 x 900
2 x 900
3 x 900
140
120
100
80
60
40
20
0
0 250 200 150 100 50
300
Solar fluid at 30˚C
]r
a
b
m[
Volume flow [l/h]
Pr
e
s
sur
e lo
s
s
1000 W/m 2
Insolation
800 W/m 2
Insolation
300 W/m 2
Insolation
Temperature difference (collector/ambient) [K] VKF 900
Fig. 4.8 Pressure loss auroTHERM VFK 900