Viessmann VITOFLEX 300-UF Quick start guide

Viesmann VITOFLEX 300-UF
Solid fuel boiler 390 to 1250 kW
VITOFLEX 300-UF
Fully automatic solid fuel boiler with grate combustion
for the combustion of woodchips, wood pellets, shavings and
mixed wood
5682428 GB 5/2019
Technical guide

Index
1. Principles of wood combustion 1. 1 Principles of wood combustion for generating heat .................................................. 6
■ General principles ................................................................................................. 6
■ Determining the amount of fuel required ............................................................... 7
■ Energy density of various fuel types compared with fuel oil (standard values) ..... 8
1. 2 Principles of wood pellet combustion for generating heat ........................................ 8
■ What are wood pellets? ........................................................................................ 8
■ Pellet requirements ............................................................................................... 8
■ Pellet quality characteristics .................................................................................. 9
■ Types of pellet delivery ......................................................................................... 9
1. 3 Principles of woodchip combustion for generating heat ........................................... 9
■ What are woodchips? ........................................................................................... 9
■ Definition of woodchip size classes according to EN ISO 17225-4 ...................... 9
■ Woodchip requirements ........................................................................................ 9
■ Substances ........................................................................................................... 10
■ Non-wood biomass fuels ....................................................................................... 10
1. 4 German Immissions Ordinance (1st BlmSchV) ........................................................ 10
■ Contents of the 1st BImSchV ................................................................................ 10
■ Update of the 1st BImSchV – Tightening of the emission limits ........................... 10
■ Emission limits for dust and carbon monoxide (CO) according to 1st BImSchV,
stage 2 (Article 5) .................................................................................................. 11
2. Vitoflex 300-UF 2. 1 Product description ................................................................................................... 12
■ Benefits at a glance .............................................................................................. 12
■ Delivered condition ............................................................................................... 12
2. 2 Specification ............................................................................................................. 14
■ Specification .......................................................................................................... 14
■ Dimensions ........................................................................................................... 16
3. Control unit 3. 1 Ecocontrol specification ............................................................................................ 19
■ Description ............................................................................................................ 19
■ Ecocontrol function ............................................................................................... 19
■ Operation .............................................................................................................. 19
■ Standard delivery package for Ecocontrol ............................................................ 19
3. 2 Accessories for Ecocontrol ....................................................................................... 20
■ External drive switching without light barrier ......................................................... 20
■ External drive switching with light barrier .............................................................. 20
3. 3 Accessories for Ecocontrol output management ...................................................... 21
■ Additional heat generator demand (peak load heat generator) ............................ 21
■ Cylinder management with 5 sensors (QM) .......................................................... 21
■ External demand ON/OFF .................................................................................... 21
■ Output signal 0-10 V ............................................................................................. 21
3. 4 Accessories for Ecocontrol remote transfer/remote monitoring ................................ 22
■ Analogue fault message device with battery ......................................................... 22
■ Exporting operating data via Modbus TCP/IP ....................................................... 22
■ External visualisation (hardwired) ......................................................................... 22
3. 5 Accessories for Ecocontrol function extension ......................................................... 23
■ Controller module .................................................................................................. 23
■ Data cable 10 m long ............................................................................................ 23
3. 6 Accessories for function extension sensors .............................................................. 24
■ Temperature sensor for heating circuit .................................................................. 24
3. 7 Controller for boiler sequence control/charging control panel .................................. 25
■ Charging control panel without boiler sequence control ....................................... 25
■ Charging control panel with boiler sequence control ............................................ 25
■ Buffer controller with boiler sequence control ....................................................... 25
4. Installation accessories 4. 1 Boiler accessories ..................................................................................................... 26
■ Flue gas recirculation ............................................................................................ 26
■ Displacer rods ....................................................................................................... 26
■ Automatic ignition system ..................................................................................... 26
■ Pneumatic cleaning ............................................................................................... 26
■ Feed screw conveyor, 2-stage .............................................................................. 27
4. 2 Boiler accessories for safety equipment ................................................................... 28
■ Thermally activated safety valve 100 °C ............................................................... 28
■ Safety valves ......................................................................................................... 28
■ Water level limiter ................................................................................................. 28
■ Maximum pressure limiter 0 to 6 bar ..................................................................... 28
■ Minimum pressure limiter 0 to 6 bar ...................................................................... 28
■ Fitting assembly with pressure gauge ................................................................... 28
■ Flash trap replacement set ................................................................................... 28
Index
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4. 3 Heat distribution accessories .................................................................................... 29
■ Motorised three-way valve (return temperature raising facility) ............................ 29
■ Circulation pumps ................................................................................................. 29
4. 4 Accessories for flue gas dust extraction ................................................................... 30
■ Flue gas dust extractor with ash container ........................................................... 30
4. 5 Accessories for flue gas routing ................................................................................ 33
4. 6 Accessories for sound insulation measures ............................................................. 34
■ Anti-vibration fittings .............................................................................................. 34
4. 7 Accessories for ash removal ..................................................................................... 35
■ Ash removal into an ash container ........................................................................ 35
■ Combustion chamber screw conveyor extension ................................................. 36
■ Extension for steeply inclined screw conveyor ..................................................... 37
4. 8 Mobile cleaning equipment accessories ................................................................... 38
■ Cleaning set with ash vacuum cleaner, 90 l .......................................................... 38
■ Cleaning set with ash vacuum cleaner, 240 l ........................................................ 38
■ Ash vacuum cleaner ............................................................................................. 38
■ Ash vacuum cleaner accessories ......................................................................... 39
■ Accessories for mobile cleaning equipment, ash containers ................................ 39
4. 9 Burn-back protection devices (RSE) ......................................................................... 40
■ Rotary lock valve ................................................................................................... 40
■ Shut-off gate valve MA 220 ................................................................................... 40
■ Drop chute L = 1.0 m ............................................................................................ 41
■ Special adaptor ..................................................................................................... 41
5. Fuel discharge 5. 1 Application options for extraction system by fuel ...................................................... 42
■ Overview ............................................................................................................... 42
5. 2 Fuel extraction with screw conveyor ......................................................................... 43
■ Pellet extraction screw conveyor, D = 120 mm ..................................................... 43
■ Specification .......................................................................................................... 43
■ Pellet discharge screw conveyor drive .................................................................. 44
5. 3 Fuel discharge with agitators .................................................................................... 45
■ Horizontal discharge AH ....................................................................................... 45
■ Specification .......................................................................................................... 45
■ Discharge screw conveyor AH to horizontal discharge AH ................................... 48
■ Additional discharge screw conveyor AH, per m .................................................. 48
■ Substructure AH .................................................................................................... 50
■ Protective panel AH for the fuel store wall ............................................................ 51
■ Cover panel AH for wood pellets .......................................................................... 51
5. 4 Fuel extraction with funnel discharge ....................................................................... 52
■ Funnel discharge AP ............................................................................................. 52
■ Specification .......................................................................................................... 52
■ Additional outlet flange AP .................................................................................... 53
■ Funnel, large ......................................................................................................... 53
5. 5 Fuel extraction with hydraulic push floor discharge system ...................................... 54
■ Specification for push floor discharge ................................................................... 54
■ Pushrod discharge ................................................................................................ 54
■ Maximum dumping heights ................................................................................... 54
■ Pushrod drive specification ................................................................................... 54
■ Forces on the building ........................................................................................... 55
■ Applications of push floor discharge ..................................................................... 55
■ Slot discharge for pulling ....................................................................................... 55
■ Centre discharge ................................................................................................... 57
■ Slot discharge with fill function .............................................................................. 59
■ Hydraulic assemblies for moving floor discharge .................................................. 61
■ Pushrod ................................................................................................................. 61
■ Pushrod drive, individual ....................................................................................... 61
■ Weld base, pushrod drive, individual .................................................................... 61
■ Pushrod drive, twin ............................................................................................... 61
■ Weld base, pushrod drive, twin ............................................................................. 62
■ Bunker weld base (fuel store) ............................................................................... 62
■ Hydraulic unit, AS single ....................................................................................... 62
■ Hydraulic drive, AS twin ........................................................................................ 63
■ Push floor screw conveyor, D = 190 mm .............................................................. 63
■ Push floor screw conveyor, D = 250 mm .............................................................. 64
■ Push floor screw conveyor drive, standard ........................................................... 64
■ Drive, push floor screw conveyor, high power ...................................................... 64
■ Push floor screw conveyor cover .......................................................................... 64
6. Fuel transport 6. 1 Application options for transport systems by fuel ..................................................... 65
■ Overview ............................................................................................................... 65
6. 2 Fuel transport with screw conveyor .......................................................................... 66
Index (cont.)
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■ Trough screw conveyor ......................................................................................... 66
■ Standard trough screw conveyor drive ................................................................. 66
■ Pipe screw conveyor ............................................................................................. 67
■ Pipe screw conveyor drive, pellets ........................................................................ 68
■ Pipe screw conveyor drive, standard .................................................................... 69
■ Pipe screw conveyor drive, high power ................................................................ 69
7. Fuel storage 7. 1 Fuel storage in on-site pellet store ............................................................................ 70
■ Sizing the pellet storage room .............................................................................. 70
■ Pellet storage room design and required system components ............................. 71
■ Additional safety instructions for pellet stores ....................................................... 72
■ Protective boards with Z brackets ......................................................................... 72
■ Fill connector and return air connector ................................................................. 72
■ Accessories for the on-site pellet store ................................................................. 75
7. 2 Filling the on-site fuel store ....................................................................................... 77
■ Manual silo cover FDM 2.9/1.3 m ......................................................................... 77
■ FDH hydraulic bunker cover ................................................................................. 78
■ Fall protection grille 120 for FDH .......................................................................... 80
■ Fall protection grille 200 for FDH .......................................................................... 80
■ FDB drive-over bunker cover ................................................................................ 80
■ Fall protection grille 120 for FDB .......................................................................... 82
■ Fall protection grille 200 for FDB .......................................................................... 82
■ Shaker motor for fall protection grille .................................................................... 82
■ Hydraulic unit for bunker charging cover .............................................................. 82
■ Cover drive for hydraulic unit ................................................................................ 83
8. Heating water buffer cylinder 8. 1 Heating water buffer cylinder on request .................................................................. 84
■ Heating water buffer cylinder (customised) ........................................................... 84
9. Design information 9. 1 System design .......................................................................................................... 84
■ Selecting the rated heating output ........................................................................ 84
■ Safety temperatures .............................................................................................. 84
9. 2 Delivery ..................................................................................................................... 84
■ Lifting the solid fuel boiler ..................................................................................... 84
9. 3 Positioning ................................................................................................................ 84
■ Handling ................................................................................................................ 84
■ Boiler room requirements ...................................................................................... 85
■ Boiler room floor requirements .............................................................................. 85
■ Requirements of the Muster-Feuerungsverordnung [M-FeuVo Sample Combus-
tion Ordinance - Germany] .................................................................................... 86
■ Combustion air supply .......................................................................................... 86
■ Safety precautions ................................................................................................ 87
■ Minimum clearances ............................................................................................. 87
9. 4 Water connection ...................................................................................................... 88
■ Heating connections ............................................................................................. 88
■ Boiler circuit and shunt pump ................................................................................ 88
■ System example ................................................................................................... 88
■ Sizing the expansion vessel .................................................................................. 90
9. 5 Electrical installation ................................................................................................. 91
■ Requirements ........................................................................................................ 91
■ Positioning the control panel ................................................................................. 91
9. 6 Safety equipment to EN 12828 ................................................................................. 91
9. 8 Safety equipment to protect against overfilling with fuel and burn-back ................... 92
■ Automatic extinguishing device (SLE) .................................................................. 92
■ Preventing overfilling with fuel .............................................................................. 93
■ Burn-back protection device (RHE) ...................................................................... 93
■ Reignition protection (RZS) ................................................................................... 93
■ Temperature and flame monitor (TÜF, FÜF) ......................................................... 93
■ Burn-back protection device (RSE) ....................................................................... 94
9. 9 Fire safety ................................................................................................................. 94
■ Fuel store fire safety ............................................................................................. 94
9.10 Commissioning ......................................................................................................... 94
■ Fuel for commissioning ......................................................................................... 95
■ Amount of fuel to be stored for commissioning ..................................................... 95
9.11 Fuels ......................................................................................................................... 95
9.12 Standard values for water quality ............................................................................. 95
■ Heating systems with rated operating temperatures up to 100 °C (VDI 2035) ..... 95
■ Filling the heating system ..................................................................................... 96
9.13 Frost protection ......................................................................................................... 96
9.14 Connection on the flue gas side ............................................................................... 96
■ Chimney ................................................................................................................ 96
Index (cont.)
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■ Flue pipe ............................................................................................................... 96
9.15 Sound insulation ....................................................................................................... 97
10. Appendix 10. 1 General information on low pressure hot water boilers with safety temperatures of
up to 110 °C .............................................................................................................. 97
10. 2 Pipe connections ...................................................................................................... 98
10. 3 Electrical installation ................................................................................................. 98
10. 4 Operating instructions ............................................................................................... 98
10. 5 Checks as part of the Building Regulations approval procedure .............................. 98
11. Keyword index ............................................................................................................................................ 99
Index (cont.)
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1.1 Principles of wood combustion for generating heat
General principles
Net calorific value of wood biomass as a function of moisture
content
The energy content of wood is given as the net calorific value Hu.
The net calorific value is the energy that can be obtained from burn-
ing one kilogram of damp wood. The water contained in the flue gas
is present in the form of water vapour. The gross calorific value Ho
additionally takes account of the latent heat of condensation in the
water vapour, which is released as it cools back down to the initial
temperature.
The moisture content of a fuel charge is the main factor that influen-
ces combustion. It determines the energy content and therefore the
energy conversion that can be achieved during combustion. In prac-
tice, the net calorific value of fuels is between 5.0 kWh/kg (18 MJ/kg)
at a moisture content of 5 % and 1.5 kWh/kg (5.4 MJ/kg) at a mois-
ture content of 60 %. This net calorific value depends on the type of
wood and, more importantly, on the moisture content or moisture
level in the wood. The moisture content is crucial for controllability at
partial load and the emissions performance of the system.
Determining the moisture content
The moisture content is determined with the drying cabinet method
on which the CEN (European Committee for Standardisation) stand-
ard is based. As part of this, a fuel sample is weighed when wet,
dried in a drying cabinet at approx. 105 °C for several hours, and
then weighed again. The proportion of water in the fuel is given as
the moisture content (M).
Net calorific value of wood in relation to moisture content (M)
0 10 20 30 40 50 60
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
0 11 25 43 67 100 150
0
2
4
6
8
10
12
14
16
18
20
Net cv (Hu) in MJ/kg
Water content (w) in %
Moisture level (u) in %
Net cv (Hu) in kWh/kg
A
B
ASoftwood
BHardwood
Principles of wood combustion
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Net calorific value for various types of wood, source: Technologie- und Förderzentrum (Technology and Support Centre) (TFZ)
Straubing, Bavaria, Germany
Water content in % 0 10 20 30 40 50
Type of tree Unit of measurement
Spruce kWh/kg 5.20 4.64 4.05 3.44 2.86 2.27
kWh/smt 2245 2020 1979 1863 1805 1726
kWh/stcm 1249 1177 1096 1039 1005 958
kWh/tcm 925 872 812 770 745 709
Scots pine kWh/kg 5.33 4.75 4.14 3.53 2.94 2.33
kWh/smt 2613 2441 2239 2170 2114 2009
kWh/stcm 1454 1354 1243 1209 1170 1116
kWh/tcm 1077 1003 921 895 867 827
Beech kWh/kg 11.00 4.53 3.97 3.39 2.81 2.22
kWh/smt 3475 3187 2899 2704 2609 2482
kWh/stcm 1757 1613 1458 1361 1315 1252
kWh/tcm 1432 1314 1188 1109 1072 1020
Oak kWh/kg 5.00 4.50 3.92 3.33 2.66 2.19
kWh/smt 3336 3091 2836 2760 2576 2543
kWh/stcm 1687 1557 1432 1396 1349 1283
kWh/tcm 1375 1269 1166 1138 1099 1045
Relation of moisture content (w) to moisture level in fuel (u)
The proportion of water in woodchips and wood pellets is given as
either the moisture content or the fuel moisture level. The moisture
content (in %) is relative to the moist fuel mass or the fresh sub-
stance (FS); the fuel moisture level is relative to the absolutely dry
fuel mass (TS).
Example:
If 100 kg of fuel contains 50 kg of water, the fuel has a moisture con-
tent of 50 % (w50) and a fuel moisture level of 100 % (u = 100).
u [%] = w [%] x 100
100 ― w [%]
0 20 40 60 80 100 120 140 160 180 200
0
10
20
30
40
50
60
70
Fuel moisture level (u) in %
Water content (w) in %
Determining the amount of fuel required
The amount of fuel required can be calculated on the basis of the net
calorific value and the required rated heating output. Significant influ-
encing factors for this are the moisture content of the fuel and the
efficiency of the system.
B = QN
Hu x η
Principles of wood combustion (cont.)
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B Amount of fuel required in kg/h
QNRequired rated heating output in kW
HuNet calorific value in kWh/kg
η System efficiency in %
Energy density of various fuel types compared with fuel oil (standard values)
Tip/
Stack density
Fuel oil equivalent
kilogram
Fuel oil equivalent
litre
840 kg/m³
0.84 kg
1.00 l
Fuel oil
860 kg/t.m³
1.28 kg
1.49 l
Anthracite
650 kg/t.m³
2.16 kg
3.33 l
Wood pellets
459 kg/t.m³
2.35 kg
5.11 l
Beech logs
297 kg/t.m³
2.30 kg
7.73 l
Spruce logs
217 kg/t. m³
2.25 kg
10.36 l
Woodchips
1.2 Principles of wood pellet combustion for generating heat
What are wood pellets?
Wood pellets are made from 100 percent natural wood remnants. This raw material is waste matter created by the wood industry in large
volumes through planing or sawing. Wood remnants are compressed under high pressure and formed into pellets, i.e. pressed into a cylindri-
cal shape.
The raw material is stored and transported under completely dry conditions. System users should also ensure completely dry storage condi-
tions. This is the only way to guarantee optimum and effective combustion.
Pellet requirements
For heat generation, use wood pellets that have the following proper-
ties:
■ Diameter of 6 mm
■ Length of 3.15 to 40 mm (1 % up to 45 mm)
■ Max. moisture content of 10 %
The wood pellets used for combustion in the solid fuel boiler must
correspond to the requirements of EN ISO 17225-2.
Requirement ENplus-A1 EN ISO 17225-2 quality A1
Diameter mm 6 ± 1 D06
Length mm A maximum of 1 % may be lon-
ger than 40 mm, but no longer
than 45 mm.
3.15 to 40
Bulk density in the delivered condition kg/m³ 600 to 750 BD600
Net calorific value in the delivered condition MJ/kg
kWh/kg
≥ 16.5
≥ 4.6
Q16.5
Q4.6
Water content in the delivered condition m-% ≤ 10 M10
Fines content in the delivered condition m-% ≤ 1 F1.0
Mechanical strength in the delivered condition m-% ≥ 97.5 DU 97.5
Ash content, free from water % ≤ 0.7 A0.7
Principles of wood combustion (cont.)
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Requirement ENplus-A1 EN ISO 17225-2 quality A1
Ash softening temperature
This value is only binding for pellets certified to ENplus.
It indicates the temperature at which the wood ash is
deformed and can therefore cause fusions in the com-
bustion chamber.
°C ≥ 1200 –
Chlorine content, free from water m-% ≤ 0.02 Cl0.2
Sulphur content, free from water m-% ≤ 0.04 S0.04
Nitrogen content, free from water m-% ≤ 0.3 N0.03
m-% = percentage by mass Note
EN 14961-2 was superseded by the new standard EN ISO 17225-2
in September 2014. It describes the essential properties of wood pel-
lets.
Pellet quality characteristics
Good wood pellets:
■ Smooth, shiny surface
■ Uniform length
■ Low proportion of dust
■ Sink in water
Low quality wood pellets:
■ Cracked rough surface
■ Widely varying length
■ High proportion of dust
■ Float in water
Types of pellet delivery
In their loose form, wood pellets are transported by silo tanker and
pumped into the storage room via a hose system.
Careful handling of wood pellets ensures a low proportion of dust,
trouble-free boiler charging and a constant heating output by the
solid fuel boiler.
1.3 Principles of woodchip combustion for generating heat
What are woodchips?
Woodchips are made from 100 percent natural wood from forests
and plantations. This raw material comes from tree trunks or
branches.
The wood is then processed with high speed cutting tools in accord-
ance with EN ISO 17225.
Definition of woodchip size classes according to EN ISO 17225-4
Size class Main percentage (at
least 60 % of the
mass), a)
Fine fraction
(≤ 3.15 mm)
Coarse fraction (in
brackets particle
length)
Maximum particle
length, b)
Maximum cross-sec-
tion area of the coarse
fraction, b) c)
Size in mm In % of the mass In % of the mass in mm In cm2
P16S 3.15 to 16 ≤ 15 % ≤ 6 (> 31.5 mm) ≤ 45 ≤ 2
P31S 3.15 to 31.5 ≤ 10 % ≤ 6 (> 45 mm) ≤ 150 ≤ 4
P45S 3.15 to 45 ≤ 10 % ≤ 10 (> 63 mm) ≤ 200 ≤ 6
a) The number in the size class refers to the maximum particle size in the main percentage. The particles have to pass through a strainer
with a circular mesh (ISO 17827-1 standard), in which the sieve apertures are of the specified size for the size class. The lowest possible
property class should be specified.
b) Only determine the length and cross-sectional area of particles in the coarse fraction. In a sample of about 10 l 2 pieces at the most can
exceed the maximum length if the cross-sectional area is < 0.5 cm2.
c) To measure the cross-sectional area, you are advised to use a transparent set square, arrange the particles at right angles behind the set
square and use a cm2 grid to estimate the maximum cross-sectional area of these particles.
Woodchip requirements
For combustion in the solid fuel boiler, use woodchips of size class
P31S that have the following properties:
■ Max. coarse fraction of 6 % (> 45 mm)
■ Max. cross-section of 4 cm²
■ Max. length of 15 cm (1 % up to 45 mm)
■ Moisture content (see product description)
Principles of wood combustion (cont.)
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Bulk density of woodchips
Bulk densities of woodchips as defined by water content, according to EN ISO 17225-4
Water content based on
moisture mass
% of the mass 8 to 18 18 to 25 25 to 35 35 to 45
Bulk density for conifer-
ous species
kg/m3160 to 180 180 to 200 200 to 225 225 to 270
Property class BD150 BD150 BD200 BD200
Bulk density for decidu-
ous species
kg/m3225 to 250 250 to 280 280 to 320 320 to 380
Property class BD200 BD250 BD250 BD300
Woodchip quality characteristics
Good woodchips:
■ Low, homogeneous water content, no moisture pockets or mould
■ Low proportion of needles, leaves, fine branches and bark
■ Low proportion of fine wood material (hardly any particles < 3 mm)
■ No contamination from mineral soil and foreign matter or impurities
■ Uniform particle size (no excess length)
■ Smooth edges, no fraying
Low quality woodchips:
■ High proportion of fraying surfaces or edges
■ High proportion of needles, leaves, fine branches and bark
■ Contamination from mineral soil and foreign matter or impurities
■ Heterogeneous particle size
■ High fine fraction and water content
Substances
When buying wood for combustion, it is important to ensure that the
following foreign matter is avoided:
■ Stones
■ Metal particles
■ Masonry remnants
■ Plastics
Foreign matter changes the composition of the fuel and therefore the
critical parameters of the combustion process.
Observe the following limits per kg of dry fuel or dry matter content
of non-combustible constituents. The limits for ash were determined
at an analysis temperature of 815 °C. If the specifications are
observed, the minimum temperature at which ash sintering starts is
1000 °C.
Limit Comparison with natural wood from forests
Chlorine Cl mg/kg Max. 300 10
Sulphur S mg/kg Max. 1000 120
Total Cl, S mg/kg Max. 1000 130
Ash content, total g/kg Max. 15.0 5.0
Sum of alkali oxides in the ash (K2O and Na2O) g/kg Max. 1.0 0.35
Start of ash sintering (SB) °C min. 1000 approx. 1200
Note
Avoid foreign matter, such as nails and iron particles, as such foreign
bodies increase the wear of system parts.
It is imperative that light metals are avoided, as these will melt in the
combustion chamber and lead to faults in the grate area.
Exceeding the above limits will shorten the service life of the com-
bustion chamber and the solid fuel boiler. This also means a greater
amount of maintenance work and shorter service intervals.
Non-wood biomass fuels
Non-wood biomass fuels such as needles, leaves, cereals, straw,
husks, fruit stones, etc. are unsuitable as fuels for trouble-free oper-
ation, and are therefore not permitted.
In some cases, the fuel properties (elemental composition, ash sin-
tering point, etc.) differ considerably from those of wood. Combus-
tion of such fuels in a solid fuel boiler can lead to an impairment of
the combustion characteristics. The fireclay lining and the heat
exchanger surfaces will be subject to increased stress. Warranty
claims can therefore only be asserted when using approved fuels.
1.4 German Immissions Ordinance (1st BlmSchV)
Contents of the 1st BImSchV
The German Immissions Order (1st BImSchV) regulates the follow-
ing for small and medium-scale biomass combustion systems which
do not require approval:
■ The conditions under which small and medium-scale biomass
combustion systems may be installed and operated.
■ Establishing the emission limits of small and medium-scale sys-
tems
■ How often and to what extent a system must be monitored in order
to protect the environment from emissions.
Update of the 1st BImSchV – Tightening of the emission limits
The update of the 1st BImSchV, which contains the following essen-
tial new points, came into force from 22 March 2010 onwards:
Principles of wood combustion (cont.)
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■ Control of the emission limits for solid fuel boilers with a rated
heating output of 4 to 1000 kW
■ Verification of the required emission limits in the form of periodic
on-site measurements to be carried out by the flue gas inspector
when commissioning new systems (with subsequent periodic
checks every 2 years)
■ Emission limits tightened to 20 mg/m³ for dust and to 400 mg/m³
for CO in the 1st BImSchV, stage 2
■ After a transitional period, emission limits will also apply to old sys-
tems.
■ Design of the heating water buffer cylinder in hand charged sys-
tems: Min. 12 litres per litre fuel hopper or 55 litres/kW rated boiler
heating output
■ Design of the heating water buffer cylinder in automatically
charged systems: Min. 20 litres/kW rated boiler heating output
Emission limits for dust and carbon monoxide (CO) according to 1st BImSchV, stage 2 (Article 5)
Note
Emission limits in periodic on-site measurements (relative to 13 %
oxygen)
Fuel according to
Article 3, para-
graph 1
For new systems
installed
Rated heating out-
put
in kW
Dust
in mg/m³
CO
in mg/m³
Solid fuel boilers af-
fected
Pellets From 1 January 2015 ≥ 4 to ≤ 1000 ≤ 20 ≤ 400 Vitoligno 300-C
Vitoligno 300-H
Vitoflex 300-RF
Vitoflex 300-UF
Woodchips From 1 January 2015 ≥ 4 to ≤ 1000 ≤ 20 ≤ 400 Vitoligno 300-H
Vitoflex 300-RF
Vitoflex 300-UF
Natural non-bulky
pieces of wood (saw-
dust, shavings, sand-
ing dust), wood bri-
quettes
From 1 January 2015 ≥ 4 to ≤ 1000 ≤ 20 ≤ 400 Vitoligno 250-S
Vitoligno 300-S
Vitoflex 300-RF
Vitoflex 300-UF
Logs From 1 January 2017 ≥ 4 to ≤ 1000 ≤ 20 ≤ 400 Vitoligno 150-S
Vitoligno 200-S
Vitoligno 250-S
Vitoligno 300-S
Note on dust emission limits
Depending on both the type of fuel used, e.g. wood pellets or wood-
chips, and fuel quality (according to EN ISO 17225) additional emis-
sion reduction measures may be required in order to adhere to the
dust emission limits demanded by the 1st BImSchV.
These are secondary measures, such as a fine-dust filter (e.g. an
electrostatic filter) or tertiary measures in the form of the support of a
Viessmann engineer when measuring. Viessmann should be consul-
ted on this.
VDI 4207, Sheet 2 (Emission measurements at small firing installations)
VDI 4207, Sheet 2 (Emission measurements at small firing installa-
tions) specifies the requirements for the initial and periodic testing
and measurement of dust emissions in accordance with the
1st BImSchV or the Kehr- und Überprüfungsordnung (KÜO - sweep-
ing and inspection regulation) when using solid fuels. Also described
are the system and operation-related measures that need to be
implemented in advance in order to ensure that the emissions meas-
urements are carried out correctly.
Principles of wood combustion (cont.)
VITOFLEX 300-UF Viesmann 11
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2.1 Product description
AThree-pass boiler
BExternal grate with primary air 2
CSafety heat exchanger
DSecondary air
EIgnition fan
FFeed screw conveyor with barrier layer
GCombustion retort with internal grate and primary air 1
HAsh removal
KCombustion chamber door
LMoving infeed grate
MPneumatic cleaning
The Vitoflex 300-UF grate combustion system 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). It combines the benefits of underfeed combustion with
the advantages of grate combustion to optimum effect. The
Vitoflex 300-UF grate combustion system is characterised by highest
efficiency levels and perfect combustion in all load stages. The hori-
zontal heat exchanger with pneumatic cleaning is ideal for the use of
fuel with a high percentage of fines.
The ash is removed automatically from the combustion base and
transported into a standard container. Efficiency of over 90 % ena-
bles maximum seasonal efficiency in modulating operating mode.
Use of the Vitoflex 300-UF as a base load boiler is practical for build-
ing heat loads of 300 kW and above. Combination with a solar ther-
mal system is also easily possible. The Vitoflex 300-UF is tested and
approved in accordance with EN 303-5. It is also manufactured in
accordance with the Machinery Directive and has a CE designation.
It is also subject to on-going inspections by TÜV.
Benefits at a glance
■ High efficiency thanks to proven combustion technology, three-
pass heat exchanger, modulating output control and regulated pri-
mary and secondary air supply.
■ Easy servicing thanks to fully automatic ash removal and optional
pneumatic cleaning system.
■ Highly developed safety equipment ensures safe and reliable
operation.
■ Optimum system output results from the design and delivery of all
system components from a single source.
■ Automatic ignition precludes the need for firebed maintenance and
saves fuel.
Option: For fuels with less than 40 % moisture content (< M40)
only.
■ Individual design of your system by our team of experts.
■ Output control from 30 to 100 %
Delivered condition
■ Fully assembled steel boiler for wood pellets and woodchips:
– Combustion block with combustion retort:
– Sloping external grate
– Moving burnout grate
– Combustion chamber door
– Ash doors
– Ash pans
– Boiler with horizontal heat exchanger
– Cleaning equipment
■ Flue gas fan
■ Ventilation air fan (primary and secondary air fan)
■ Feed screw conveyor with barrier layer:
– Extinguishing valve with dirt trap
– Extinguishing water container with retainer
Standard delivery for sensors:
■ Sensors on the combustion block and in the flue outlet:
– Limit switch, combustion chamber door
– Positive pressure limiter
– Negative pressure sensor
– NiCrNi combustion chamber temperature sensor
– Infrared light barriers, fuel level monitoring in combustion cham-
ber
– Zirconium dioxide probe with measured value transducer
(Lambda probe)
– Pt1000 flue gas temperature sensor with 1/2" x 280 mm sensor
well
■ Sensors and switches installed at top of boiler:
– Pt1000 boiler water temperature sensor in flow connector
– Pt1000 return temperature sensor in return connector
– High limit safety cut-out
Vitoflex 300-UF
12 Viesmann VITOFLEX 300-UF
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■ Sensors and switches installed on the feed screw conveyor: – Infrared light barrier for level monitoring of the barrier layer for
the feed screw conveyor
– Safety limit switch on inspection cover of feed screw conveyor
– Pt1000 contact temperature sensor on the feed screw conveyor
■ Sensor in the low loss header (installation on site):
– Pt1000 system sensor with sensor well 1/2" x 280 mm (B28.1)
Vitoflex 300-UF (cont.)
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2.2 Specification
Specification
Rated heating output kW 390 530 720 950 1250
Min. heat transfer kW 117 159 216 285 375
Fuel efficiency kW 424 576 783 1033 1359
Performance data
Rated heating output with standard fuel M45*1 kW 390 530 720 950 1250
Rated constant heating output with standard
fuel M45*2
kW 370 503 648 855 1125
Minimum heating output Qmin*3 kW 117 159 216 285 375
Heating data
Flow temperature
–Permissible*4 (safety temperature) °C 100 100 100 100 100
–Maximum*5 °C 95 95 95 95 95
–Minimum*5 °C 75 75 75 75 75
Minimum return temperature °C 65 65 65 65 65
Permiss. operating pressure
Boiler bar 6 6 6 6 6
MPa 0.6 0.6 0.6 0.6 0.6
Test pressure bar 8.6 8.6 8.6 8.6 8.6
MPa 0.86 0.86 0.86 0.86 0.86
Safety heat exchanger bar 3 - 6 3 - 6 3 - 6 3 - 6 3 - 6
MPa 0.3 - 0.6 0.3 - 0.6 0.3 - 0.6 0.3 - 0.6 0.3 - 0.6
Thermally activated safety valve l/h - - - - -
Water flow rate
Flow rate (10 K diff.) m³/h 33.54 45.58 61.92 81.70 107.50
Flow rate (15 K diff.) m³/h 22.36 30.39 41.28 54.47 71.67
Flow rate (20 K diff.) m³/h 16.77 22.79 30.96 40.85 53.75
Pressure drop on the water side
Pressure drop on the water side (10 K diff.) Pa 2314 4274 7888 5844 10118
Pressure drop on the water side (15 K diff.) Pa 1029 1900 3506 2597 4497
Pressure drop on the water side (20 K diff.) Pa 579 1069 1972 1461 2529
Heating surface m225.44 33.88 49.47 66.75 79.04
Total dimensions
Total length mm 4370 4870 5257 5447 5992
Total width (boiler) mm 1274 1247 1380 1612 1612
Total width (boiler with feed screw conveyor) mm 2382 2382 2488 2852 2852
Total height (boiler) mm 2378 2536 2834 3035 3230
Total height (boiler with flue gas fan) mm 3186 3186 3378 3452 3717
Weight
Boiler kg 1680 2707 3291 4874 5563
Combustion block kg 2970 4238 4953 5779 6520
Displacer rods kg - - 394 538 538
Flue gas fan kg 60 62 78 82 107
Feed screw conveyor kg 153 153 153 190 190
Total dry weight kg 4863 7160 8869 11463 12919
Total wet weight kg 6076 8604 10730 13406 15400
Capacity
Boiler water l 1213 1444 1861 1943 2482
Content on hot gas side l 1540 2280 2830 4050 5210
Ash box, grate ash l 240 240 240 240 240
Ash box, flue gas dust extractor l 240 240 240 240 240
*1 When the boiler and combustion chamber have been cleaned and the boiler is equipped with pneumatic boiler cleaning.
*2 Levelled output when boiler is used as base load boiler in continuous operation, equipped with pneumatic boiler cleaning and a runtime
(time between 2 boiler cleaning operations) of 600 hours
*3 Q ≥ Qmin: Output operation modulating control (variable output control)
Q ≤ Qmin: Low load with ON Qmin/ OFF (stop and go operation)
*4 Shutdown temperature of the high limit safety cut-out
*5 Temperature adjustable at the control unit
Vitoflex 300-UF (cont.)
14 Viesmann VITOFLEX 300-UF
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Rated heating output kW 390 530 720 950 1250
Max. power consumption
Ignition unit W 1600 1600 1600 1600 1600
Electrical connections (total) W 6340 8420 8420 10920 11920
During heating operation W 2880 3570 4560 5170 6790
Feed screw conveyor W 1100 1500 1500 2200 2200
Primary air fan 1 W 220 250 250 550 550
Primary air fan 2 W 550 550 550 550 550
Primary air fan 3 W 900 900 900 900 900
Secondary air fan W 550 1500 1500 1850 1850
Flue gas fan W 1500 2200 2200 3000 4000
Grate drive W 120 120 120 120 120
Electrical power consumption at QNW 2880 3570 4560 5170 6790
Electrical power consumption at Qmin W 2340 2900 3710 4150 5470
Boiler connections
Boiler flow DN 100 100 100 125 125
Boiler return DN 100 100 100 125 125
Extinguishing water connection R ¾ ¾ ¾ ¾ ¾
Boiler drain valve R 1 1 1½ 2 2
Safety heat exchanger
Cold water R 2 x ½ 2 x ½ 4 x ½ 4 x ½ 4 x ½
DHW R 2 x ½ 2 x ½ 4 x ½ 4 x ½ 4 x ½
Sensor well for thermally activated safety
valve (TS)
RP ½ ½ 2 x ½ 2 x ½ 2 x ½
Flue gas*6
Average temperature (gross*7)
Average flue gas temperature at QN*8 °C 160 160 160 160 160
Average flue gas temperature at Qmin °C 120 120 120 120 120
Mass flow rate
QN, M5, O2 6 % g/s 289.4 393.2 534.2 704.8 927.4
QN, M45, O2 8 % g/s 348.1 473.1 642.7 848.0 1115.8
Flow rate
QN, M5, O2 6 %, 150 °C m3/s 0.32 0.43 0.59 0.78 1.02
QN, M45, O2 8 %, 150 °C m3/s 0.40 0.54 0.74 0.98 1.29
Flue outlet 7 mm 350 350 350 400 450
Required draught
– Required at full load Pa 5 5 5 5 5
mbar 0.05 0.05 0.05 0.05 0.05
Max. permissible draught*9 Pa 10 10 10 10 10
mbar 0.1 0.1 0.1 0.1 0.1
Efficiency
–Full load*10 % 94.8 93.8 92.8 91 91
– Partial load % 92.9 93.1 93.3 90 90
CE designation in accordance with the Machi-
nery Directive
CE CE CE CE CE
Boiler category to EN 303-5 5 5 5 3 3
*6 Values for calculating the size of the flue system to EN 13384, based on 12 % O2.
*7 Actual flue gas temperature as average gross value in line with EN 304 at 20 °C combustion air temperature, based on 12 % O2.
*8 Flue gas temperature: Reduction possible by employing the displacer rods (QN-20 °C; Qmin - 10 °C)
*9 In chimneys with a draught (chimney draught) above 0.15 mbar, a secondary air device (draught limiter) must be installed.
*10 Lower for dry fuel (M5-M20) without recirculation.
Lower for Vitoflex 300-UF, 720 to 1250 kW without displacer rods
Vitoflex 300-UF (cont.)
VITOFLEX 300-UF Viesmann 15
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Dimensions
p
o
678
c
a b
f e
470
g
h
KR KV
d
m
800
n
k
l
q.
940
KR Boiler return
KV Boiler flow
Dimensions
Rated heating output kW 390 530 720 950 1250
a mm 2378 2536 2834 3035 3230
b mm 2328 2486 2784 2981 3176
c mm 4370 4870 5257 5447 5992
d mm 2060 2560 2562 2562 3107
e mm 577 577 577 657 657
f mm 1200 1200 1200 1275 1275
g mm 2405 2905 2993 2861 3406
h mm 1086 1086 1380 1612 1612
k mm 803 803 803 929 929
l mm 453 453 453 479 479
m mm 2077 2331 2491 2444 2639
n mm 308 308 308 440 440
o mm 1274 1274 1380 1612 1612
p mm 1263 1417 1413 1317 1566
q mm 2077 2220 2491 2444 2639
Vitoflex 300-UF (cont.)
16 Viesmann VITOFLEX 300-UF
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Dimensions and overview of actuators and sensors
960
a
b
220
A
B
C
D
E
F
G
H
K
L
M
ASensor well for thermally activated safety valve (TAS)
BBoiler return
CReturn temperature sensor
DDrive, ash removal
EHigh limit safety cut-out
FSafety heat exchanger
GPrimary air fan 1
HBoiler water temperature sensor
KBoiler flow
LSecondary air fan
MFeed screw conveyor
Dimensions for boiler length
Rated heating output kW 390 530 720 950 1250
a mm 3282 3782 3877 3835 4380
b mm 3800 4300 4434 4392 4937
Vitoflex 300-UF (cont.)
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Overview
KR KV
B
D
C
E
F
GHK
A
M
L
N
O
V
P
Q
RS
T
U
KV Boiler flow
KR Boiler return
AAsh removal
BCleaning cover, flue gas collector
CCombustion chamber temperature sensor
DPressure sensor
ELight barrier, firebed
FIgnition unit
GCleaning cover, combustion retort
HCleaning cover, external grate
KLight barrier, ash removal
LBoiler door
MCleaning, pneumatic
NCombustion chamber door
OLimit switch, combustion chamber door
PPrimary air fan 2
QDrive, infeed grate
RContact temperature sensor, feed screw conveyor
SLimit switch, maintenance cover
TLight barrier, feed screw conveyor
UExtinguishing water connection
VBoiler drain valve
Vitoflex 300-UF (cont.)
18 Viesmann VITOFLEX 300-UF
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3.1 Ecocontrol specification
Description
For part no., see pricelist
Wood combustion system control including activation of equipment
for fuel charging according to the articles listed separately.
■ The heating output is modulated to match the heat consumption.
■ The control circuit for combustion optimisation with a Lambda
probe overlaps the output control circuit.
■ With regard to fire safety and personal safety, the highest possible
quality criteria are fulfilled.
■ Weather-compensated heating circuit control unit for up to 8 heat-
ing circuits.
Menu
Overview
OFF 10:07
Charg-
ing
0 %
Secondary air
Primary air
0.0 %
Flow Flue gas
fan
0 %
Flue gas
temp.
0.0 % 0.0 %
Ecocontrol function
■ Automatic ignition system (option)
■ Output control circuit with modulating output operation
(30 - 100 %)
– Air-controlled: Variable speed ventilation air fan subject to boiler
output.
– Exact fuel supply via the feed screw conveyor (dosing hopper
with barrier layer).
– Topping up of the dosing hopper by means of level monitoring.
– Limitation of the burning mass in the combustion chamber by
means of level monitoring.
■ Emissions-optimised control circuit: Optimisation of the air supply
through variable speed ventilation air and secondary fans with
Lambda probe measurement to ensure optimum combustion.
■ Limitation of the combustion chamber temperature with corre-
sponding variation of air ratio for protection of the fireproof lining.
■ The pressure regulator ensures constant negative pressure in the
combustion chamber.
■ Keeping up the return temperature with the boiler mixer ensures a
long boiler service life.
■ Safety functions for:
– Excess temperature
– Burn-back
– Opening of a fuel charging cover
– Forced heat transfer
■ Input terminals in the control panel for:
– 2 high limit safety cut-outs (STB)
– 2 low water indicators
– 2 positive pressure limiters (water)
– Emergency stop (external to TRVB H118)
– CO/CO2 monitoring (external)
■ Floating contacts:
– Operating message
– Fault message (important)
– Fault message (warning)
– Transfer excess heat
– Service message
Operation
Operation is via a touchscreen. All operating data can be read from
the display. The set values of all important parameters can be
entered easily. Fault messages are displayed in plain text and issued
in the sequence of occurrence.
Touchscreen:
For operating the heating system.
The touchscreen integrated into the control panel door enables visu-
alisation and graphic evaluation of the system.
Standard delivery package for Ecocontrol
■ Compact control panel
– Powder coated surface
– Version as per ÖVE/VDE guidelines, fully wired to terminal strips
– Feed 3 × 400 V, 50 Hz, control voltage 230 V or 24 V
– Control panel temperature monitoring
– Freely programmable control unit
– Hybrid motor starter for all drives priced separately
– Inverter for fan motors
■ In the control panel door
– 4-pole mains isolator
– Graphics-capable touchscreen
– Control panel fan (incl. Pt1000 control panel sensor)
– Documentation incl. fixed wiring diagram, terminal connection
diagram, operating instructions, installation instructions in the
guide folder
■ Integral LAN interface (touchscreen)
Note
The control panel must be installed on site.
For the standard delivery package for the sensors, see "Boiler deliv-
ered condition".
If extending the heating circuits, the information in the chapter
"Accessories for Ecocontrol function extension" must be observed.
Control unit
VITOFLEX 300-UF Viesmann 19
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3.2 Accessories for Ecocontrol
External drive switching without light barrier
For part no., see pricelist
Activation of an external conveyor drive or a rotary lock valve without
reversing (changing the rotational direction).
The motors are protected against overload.
Standard delivery:
■ Hybrid motor starter for the drive motor integrated into the control
panel
■ Input in control panel (safety limit switch on maintenance cover)
■ Output in control panel (external conveyor drive)
Note
■ The electrical output data of the existing conveyor device (kW,
amps, volts) must be stated.
■ The customer is responsible for delivery and installation of the
safety switches of the external conveyor drive.
■ Only with a defined limited material supply (upstream screw con-
veyor).
External drive switching with light barrier
For part no., see pricelist
Activation of an external conveyor drive without reversing (changing
the rotational direction).
If there is a risk of overfilling in the charging system, the integral light
barrier interrupts the upstream charging.
The motors are protected against overload.
Standard delivery:
■ Hybrid motor starter for the drive motor integrated into the control
panel
■ Input in control panel (safety limit switch on maintenance cover)
■ Output in control panel (external conveyor drive)
■ Infrared light barrier (screw conveyor inlet)
Note
■ The electrical output data of the existing conveyor device (kW,
amps, volts) must be stated.
■ The customer is responsible for delivery and installation of the
safety switches.
■ For the activation of a screw conveyor with external motor down-
stream of the external discharge.
Control unit (cont.)
20 Viesmann VITOFLEX 300-UF
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