Operation With Constant Flow Temperature - Viessmann Vitocell 100-H Technical Manual

Cylinder loading systems — Vitocell 100-L with Vitotrans 222
A
B
W
V
U
A DHW
B Hot water inlet from the heat exchanger
C Vitotrans 222 heat exchanger set
D Plate heat exchanger
E Heating circuit pump (primary), highly efficient
F Air vent valve
G Heating water flow
H Heating water return
K Boiler
L Temperature sensor

Operation with constant flow temperature

The Vitotrans 222 heat exchanger set is operated without a mixer
assembly. Limit the heating water temperature to 75 ºC.
The required DHW temperature and transfer output are set by adjust-
ing the circulating volume for the heating process at line regulating
valve L to the heating output of the heat exchanger (or, if the available
boiler output is lower than that of the Vitotrans 222, according to the
boiler output).
High or medium draw-off rates are covered by the DHW cylinder. Cold
water flows into the DHW cylinder to replace the hot water drawn. The
Vitotrans 222 starts when the cold water layer inside the DHW cylinder
reaches upper temperature controller T.
Does not replace the DHW cylinder safety valve to DIN 1988.
*16
DHW heating
F F F
C
N
P
R
O
S
L
D
T
(cont.)
F
G
H
E
N Mixer assembly
O Line regulating valve
P Non-return valve
R Cylinder loading pump (secondary), highly efficient
S Safety valve *16
T Common cold water connection with safety assembly to
DIN 1988
U Vitocell 100-L (here: 500 l capacity)
V Lower cylinder temperature sensor (OFF)
W Upper cylinder temperature sensor (ON)
The base load is covered by the continuous output of the
Vitotrans 222. Any additional hot water demand during peak times is
covered by the cylinder capacity.
Either at the end of drawing or whilst DHW is drawn off, the cylinder
volume is reheated to its set temperature via the Vitotrans 222. In the
fully heated state (no draw-off), cylinder loading pump N and heating
circuit pump E in the Vitotrans 222 are switched OFF.
Bearing in mind the stated set heating water and DHW temperatures,
the Vitotrans 222 heat exchanger set can be operated up to a total
hardness of 20 ºdH (total of alkaline earths 3.6 mol/m
K
3 ).
VIESMANN
25
5