Viessmann Vitosol100 - H Dual Mode DHW Heating with Heating Water Calorifiers in Series, with Vitosolic 200

4.6System design6
79
VITOSOL
4.6 System design6
Dual mode DHW heating with heating water calorifiers connected in series with Vitosolic 200
(especially suitable for large solar heating systems with 20 to 100m
2
absorber area)
DHW loading without solar energy
DHW cylinder2 is heated by the boiler.
The cylinder thermostat with cylinder
temperature sensorqP switches cylinder
loading pump qQ.
DHW loading with solar energy
Heating water calorifier heating
Solar circuit pump4 is switched ON, if
solar cell6 detects solar irradiation
above the set threshold value (solar
circulation bypass).
Circulation pump4 for heating plate
heat exchanger1 is switched ON, if a
temperature differential greater than
start−up temperature differential T
on
is
measured between temperature sensor
2 and calorifier 2 temperature sensor 3.
Pump4 will be switched OFF, if the
actual temperature falls below shutdown
temperature differential T
off
If the temperature differential between
temperature sensor5 and temperature
sensor3 is greater than start−up
temperature differential T5
on
, motorised
valve9 is opened and calorifiers 1 and 2
are heated by circulation pump7 (in
case the start−up temperature differential
WT−T
on
is exceeded, pump7 will be
started; it will be stopped if it falls below
shutdown temperature differential
WT−T
off
).
The volume flow in the calorifier loading
circuit is matched to that of the solar
circuit via line regulating valve8.
DHW heating
If the temperature differential between
calorifier 1 temperature sensor qW and
the temperature sensor of DHW cylinder
1 qE is higher than start−up temperature
differential T6
on
, circulation pumps qR
and qT are started, motorised valve wP is
opened, and DHW is loaded via plate heat
exchanger2.
Pumps qR and qT are switched OFF, and
valve wP is closed, if the actual
temperature falls below shutdown
temperature differential T6
off
.
The volume flow of the calorifier
unloading circuit and the DHW
preheating stage are matched by means
of line regulating valvesqU and qI.
For high water hardness (>20ºdH), install
a thermostatic mixing valveqO limiting
the heat exchanger flow temperature to
70ºC to prevent premature scaling up of
heat exchanger2.
Motorised valves9 and wP, which are
closed in their zero−volt condition,
prevent faulty circulation when calorifiers
are loading or discharged.
The additional function requirements (see
page 60) are met by circulation pump wQ.
5822135 GB