138
48 °C
Boiler temperature
HC1
14°C
21°C
Fig. 84
Note
A regular, internal regeneration process takes place in
the appliance.
■
Only switch the appliance off for a
maximum of
1 week
.
■
Select standby mode when switching off for longer
periods.
Functional principle in sorption mode
The cyclical, physical process of adsorption and
desorption in the sorber (sorption cycle) runs in a her-
metically sealed and maintenance-free sorption mod-
ule. To ensure that the water acting as refrigerant can
absorb environmental heat even at low temperatures,
the sorption module is vacuum-tight and has been
evacuated.
The zeolite in the sorber stores water (adsorption) and
releases it again (desorption). The heat released in
this process is used for central heating and DHW heat-
ing.
Through the additional introduction of environmental
heat (primary circuit), the efficiency of the appliance
can be increased by up to 40 % compared with pure
condensing operation.
Desorption phase
The zeolite in the sorber is saturated with water (refrig-
erant). Using heat supplied from gas combustion, the
sorber is heated and the water (refrigerant) is expelled
(desorbed) from the zeolite in the form of vapour.
The condenser is arranged around the sorber and the
secondary circuit return flows through it. This cools
down the water vapour expelled from the zeolite and
the water condenses. The condensed water flows to
the evaporator.
The condensation heat is transferred to the secondary
circuit, as is the heat recovered from gas combustion
in the flue gas heat exchanger.
The burner is switched off at the end of the desorption
phase.
Adsorption phase
Now the process circuit return flows through the
sorber. This cools the sorber and heat is transferred to
the secondary circuit.
The condensed water is pumped to a level above the
evaporator pipe coils by the evaporator pump. This
causes water to trickle onto the evaporator pipe coils.
The evaporator pipe coils are part of the primary circuit
and transfer the heat absorbed from the environment
to the water. The water evaporates.
The rising water vapour is bound (adsorbed) by the
zeolite in the sorber. The adsorption heat generated in
this process is transferred to the secondary circuit.
Operating modes
The gas adsorption heating appliance can be used in
condensing mode, sorption mode or mixed mode (cod-
ing address "14" in the
"Process"
group).
■
Condensing mode (delivered condition):
The heat for the secondary circuit is generated
exclusively by gas combustion.
■
Sorption mode:
The heat for the secondary circuit is generated
exclusively by the sorption cycle (adsorption/desorp-
tion).
■
Mixed mode (condensing and sorption operation):
The heat for the secondary circuit is generated pri-
marily by the sorption cycle (adsorption/desorption).
If heat demand increases, the burner also starts.
Condensing operation and sorption operation are
possible both in parallel and separately.
Function description
Control unit
5678 044 GB
Functions
Summary of Contents for D2RA
Page 113: ...113 Maintenance Checking the Vitotronic 200 H accessories cont 5678 044 GB Maintenance ...
Page 133: ...133 Parts lists Sorption module hydraulics cont 5678 044 GB Components ...
Page 136: ...136 0001 0002 0003 0004 0005 Fig 83 Parts lists Miscellaneous 5678 044 GB Components ...
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