Fuel For Commissioning; Amount Of Fuel To Be Stored For Commissioning; Fuels; Standard Values For Water Quality - Viessmann VITOFLEX 300-UF Technical Manual

Design information

Fuel for commissioning

As the boiler system is cold and residual humidity is also extracted
from the refractory concrete during commissioning, we recommend
using logs when heating the boiler system for the first time. The first
three hours of the heat-up process should be carried out with a low
output.
Before storing the fuel, the function of the silo discharge system
must be tested by an authorised contractor. Consequently, the fuel
should not be stored until after the authorised contractor has arrived.

Amount of fuel to be stored for commissioning

Rated heating output
390 kW
530 kW
720 kW
950 kW
1250 kW
The quantity corresponds to consumption of approx. 10 – 24 full
operating hours. This allows the discharge to be cleared quickly in
the event of a fault.

9.11 Fuels

The Vitoflex 300-UF has been specially developed for the automatic
combustion of dry and moist fuels (wood remnants, wood pellets or
woodchips from forest thinnings up to max. M50). The
Vitoflex 300-UF combines the benefits of underfeed combustion with
the advantages of grate combustion to optimum effect.
The Vitoflex 300-UF is suitable for the following fuels:

9.12 Standard values for water quality

The service life of any boiler as well as that of the complete heating
system is influenced by the quality of the water.
The cost of a water treatment facility is always going to be less than
that of repairing damage to your heating system.
Observing the following requirements is necessary to safeguard your
warranty rights. The manufacturer's warranty excludes damage due
to corrosion and scaling.
Heating systems with rated operating temperatures up to 100 °C (VDI 2035)
The water used in heating systems must comply with the chemical
values of the Drinking Water Ordinance [Germany]. If well water or
similar is used, check its suitability before filling the system.
Avoid excessive scale deposits (calcium carbonate) on the heating
surfaces. For heating systems with operating temperatures up to
100 °C, Guideline VDI 2035 Part 1 "Prevention of damage in water
heating installations - Scaling in domestic hot water supply installa-
tions and water heating installations" applies together with the fol-
lowing standard values. For more information, see the explanations
for guideline VDI 2035.
Total heating output in > 50 to
kW
Total alkaline earths in
3
mol/m
Total hardness in °dH ≤ 11.2
VITOFLEX 300-UF
(cont.)
Volume of fuel to be stored
approx. 2500 kg
approx. 3000 kg
approx. 4000 kg
approx. 5300 kg
approx. 6800 kg
> 200 to > 600
≤ 200 ≤ 600
≤ 2.0 ≤ 1.5 < 0.02
≤ 8.4 < 0.11
Note
For a list of permitted fuels for commissioning the Vitoflex 300-UF,
see the chapter on "Fuels". Page 95.
Note
■ The fuel should not be stored until after the authorised contractor
has arrived.
■ For commissioning, we also recommend providing approx. 0.5 m³
of logs. Ideally, the wood should be dry with a maximum 20 %
moisture content (M20) and edge length of between 45 and 50 cm.
■ Woodchips according to EN 17225-4 up to a moisture content of
50 % (M50/P31S)
■ Pellets to EN 17225-2, Class A2
Note
See information on fuels in chapter 1 from page 6.
The main water quality requirements are summarised below.
A chemical water treatment can be ordered from Viessmann for fill-
ing.
The standard values assume the following conditions:
■ The total volume of fill and top-up water will not exceed three times
the water content of the heating system during its service life.
■ The specific system volume is less than 20 l/kW heating output. In
multi boiler systems, apply the output of the smallest boiler.
■ All measures to prevent corrosion on the water side in accordance
with VDI 2035 Part 2 have been implemented.
Soften the fill and top-up water in heating systems with the following
conditions:
■ The total of alkaline earths in the fill and top-up water exceeds the
standard value.
■ Higher fill and top-up water volumes are expected.
■ The specific system volume is greater than 20 l/kW heating output.
In multi boiler systems, apply the output of the smallest boiler.
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Viesmann
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