HDG Compact 25, Руководство по эксплуатации

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3 Mode of operation – Fuel quality requirements
34
Wood chips from category P45 can be used as fuel in all HDG HDG
Compact 45/50/65/80 wood chip boilers. For P45 wood chips at least
75% by weight of the wood chips must measure between 8 mm and
45 mm. The fine content (<31.5 mm) may not exceed a max. of 8 % by
weight. A max. of 6% by weight of the wood chips may be more than
63 mm and 3.5% by weight may be over 100 mm. Lengths greater
than 120 mm are not permissible. The numeric value of the P cate-
gory refers to the size of the wood chips in mm, which fit through a
round opening with the indicated sieve size. The cross-section of the
outsized particles must be smaller than 5 cm
2
.
W
ATER CONTENT
When selecting fuel, note that the heating value of the wood is pri-
marily dependent on the water content. The more water contained
in the wood, the smaller the thermal value since the water vaporises
in the course of the burning process and thereby consumes heat.
This results in lower efficiency and thereby leads to greater wood
consumption. Increasing moisture in the fuel material also causes re-
duced efficiency, greater amounts of ash and smoke, as well as ma-
king it increasingly unfit for storage.
The maximum permissible water content of the wood chips for the
HDG Compact 25/35 is 20% (M30), for the HDG Compact 45/50/65/80
25% (M25).
For technical considerations, a representative thermal value is se-
lected depending on water content. For burning that is both econo-
mical and low on emissions, the thermal value should not be less
than 4 kWh/kg.
A
SH CONTENT
The ash content for wood in category A2 is higher than that of cate-
gory A1 due to the higher proportion of bark, needles and leaves.
The maximum permissible ash content of wood chips for the HDG
Compact 25/35 is 1.0 % by weight (A1.0), for the HDG Compact 45/
50/65/80 1.5 % by weight (A1.5).
Water content Moisture Thermal value
Relative wood
consumption
10.0% 11.1% 4.6 kWh/kg 87 %
20.0% 25.0% 4.0 kWh/kg 100 %
26.0% 35.0% 3.7 kWh/kg 110 %
30.0% 42.9% 3.4 kWh/kg 120 %
Table 3/4 - Thermal value depending on water content