Operation
24
Operating instructions
VITOBLOC 200 EM-530/660
version
SCR
58
4
1
4
3
5
GB
5.8
Operation of the SCR system
DANGER
Leaks in the exhaust system can
cause gas to escape!
Risk of poisoning
► No naked flames.
► Ventilate the area adequately.
► If gas escapes, shut down the
machine and leave the danger
zone.
CAUTION
The exhaust pipe, surfaces of the
mixing and reactor chambers, as well
as catalytic converter elements,
become heated and retain the
temperature for a sustained period.
Risk of burns!
► Wear personal protective
equipment (e.g. protective gloves).
WARNING
Take care when
handling AdBlue™!
Risk of contamination
► Avoid contact with skin and eyes.
► Wear personal protective
equipment (e.g. protective gloves,
safety goggles, safety shoes).
5.8.1 SCR-specific operating fluids
Ensuring a supply of AdBlue
TM
Each SCR system has an AdBlue
TM
intermediate
tank, which is located inside the CHP unit and is sized
so that operation under rated load can be maintained
for approximately one day.
If the fill level in the intermediate tank falls below a
critical level, a top-up pump is activated until the tank
has been filled again.
The top-up pump is included in the standard delivery
of the SCR system, but must be installed by the
operator (see installation instructions).
In parallel to the top-up pump, a 2-way solenoid valve
is also activated, which is fitted directly downstream of
the pump in the direction of flow. In the event of a leak
inside the pump, this valve prevents unwanted
circulation and any possible AdBlue
TM
leakage. This
valve is not part of the standard delivery
Handling AdBlue
TM
safely:
●
Avoid contact with the eyes and skin.
●
Wear personal protective equipment (e.g.
protective gloves and safety goggles)
●
After contact, wash the relevant parts of the body
with plenty of water and treat with skin care
products.
●
Change contaminated clothing.
Ensuring a compressed air supply
For correct operation, there must always be
compressed air available in sufficient quantity, quality
and at sufficient pressure (see technical description).
It can be provided either via an existing compressed
air network or via an additional air compressor with
intermediate store.
5.8.2 Commissioning and maintenance of
the SCR system
The SCR system is commissioned before delivery of
the CHP unit. If an SCR-ready system is being
upgraded to a full SCR system, Viessmann Service
will carry out commissioning.
The operator must ensure that, at the time of
commissioning of the SCR system, a suitable AdBlue
supply and compressed air supply have been installed
(version SCR only).
During any CHP unit maintenance work, the exhaust
gas values must be checked upstream and
downstream of the catalytic converter. A single
reading downstream of the catalytic converter
– as
with operation simply using an oxidation catalytic
converter
– is not sufficient! Always ensure that an
exhaust gas tester suitable for untreated emissions
(e.g. high concentrations of CO, HC, NOx, etc.) is
used.
The entire exhaust system within the CHP unit system
limit carries hot exhaust gas up to 500 °C. Heat is
only extracted from the exhaust gas outside the
compact unit. During exhaust gas testing, always pay
attention to personal safety.
PLEASE NOTE
► Before carrying out SCR system
adjustments, always ensure that
the untreated emissions
(= upstream of the catalytic
converter) meet the specification!
Only then is it practical to adjust
the SCR system metering curve.
