Operating Principle - REMEHA Gas 310 ECO Technical Information

3.2 Operating principle

Combustion air is drawn into the inlet connection from
the plant room (room ventilated version) or from outside
via the eccentric flue system (room sealed) by an air
supply fan.
On the inlet side of the fan is a specially designed
chamber (venturi unit) which takes gas from the multi-
block and mixes it in the correct proportions with the
incoming air. This mixing system ensures that the cor-
rect gas/ air ratio is delivered to the pre-mix burner at all
times.
Depending on demand (under the dictates of flow/return
sensor and other external/internal control inputs) the
'abc ® ' system determines the required boiler output.
The 'abc ' control then varies the speed of the air sup-
®
ply fan which alters the volume of air being drawn into
the venturi, this change in volume is measured using air
pressure differential which directly controls the volume
of gas also being delivered to the venturi. The resultant
controlled mixture is delivered to the premix burner.
This mixture is initially ignited by the combined ignition/
ionisation probe, which monitors the state of the flame.
Should the flame be unstable or not ignite within the
pre-set safety time cycle the controls will (after 5
attempts) shut the boiler down requiring manual inter-
vention to reset the boiler. The digital display will indi-
cate a flashing fault code confirming the reason for the
failure.
The products of combustion in the form of hot flue gases
are forced through the heat exchanger transferring their
heat to the system water, (the flue gas temperature is
reduced to approximately 5/ 8° above the temperature
of the system return water) then discharged via the con-
densate collector, to the flue gas outlet connection, to
atmosphere.
Because of the low flue gas exit temperature there will
be a vapour cloud formed at the flue gas terminal -this
is not smoke-, simply water vapour formed during the
combustion process.
If the flue gas temperature falls below dew point (55°),
water vapour (created during the combustion process)
will begin to condense out in the boiler, transferring its
latent heat into the system water, thereby increasing the
output of the boiler without increasing the gas consump-
tion.
Condensation formed within the boiler and flue system
is discharged from the boiler to an external drain via the
drain pan and siphon supplied.
The boiler can be supplied, as an option with a
second (constant temperature) return connection. This
additional connection enables the boiler to make full use
of its condensing ability whilst accepting both fixed and
variable temperature returns from the same system.
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Gas 310 ECO
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Remeha
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