SOLARFOCUS Therminator II, Installation Manual

Page: 27 / 44

Installation manual thermi
nator
II touch 27
6
Hydraulic connection
6.1 General information
Provide sufficient shut-off options
Position shut-off valves for each section (in buffer tank,
etc.) in order to minimise the quantity of water that
needs to be replaced in the event of repairs or system
extensions
Expansion tank (ADG)
Dimension the expansion tank with a capacity of 12%
of the total hydraulic system volume.
Secure the expansion tank against shut-off. To do this,
either use the shut-off options on the way to the ex-
pansion tank as cap valves, or unscrew the hand lever
(handwheel) and attach it to the expansion tank with
the wire in a clearly visible position.
Hydraulic switch
A hydraulic switch separates the flows in boiler and
heating circuits. If the heating system is operated with-
out a buffer tank, a hydraulic switch must be installed
between flow and return.
Buffer tank: Use, dimensioning
The use of a buffer tank is to be recommended in any
case, as the boiler can then always operate in the
optimum load range. This prevents frequent and un-
necessary boiler start-ups and significantly reduces
the higher fuel consumption during start phases.
A further advantage is that there is always a certain
volume available for heating, allowing a quick supply
of heat.
A buffer tank also prolongs the service life of the boiler
and reduces emissions.
For pellet boilers, a buffer tank volume of 30 litres per
kW heating output is recommended.
6.2 Fill-up water requirements
General recommendations for installation
- Fit an upstream filter (<25 µm) to prevent particles
getting into the heating water.
- Position shut-off valves for each section (in buffer
tank, etc.) in order to minimise heating water loss in
the event of repairs or system extensions.
Corrosion
Corrosion is usually triggered by the available oxygen
in the water. This value can be brought into a safe
range with proper planning, design, installation and
maintenance of the heating system.
Important in this regard:
Pressure maintenance at
regular intervals (operating pressure, pressure in
the expansion tank)
Formation of scaling
Scaling refers to heating water deposits on the heat
exchanger of the boiler. The cause of scaling is the
presence of limestone in the water. If the value (total
hardness °dH) is too high, the fill-up water must be
treated.
Parameters that play a role in the formation of scal-
ing:
- System volume (the bigger it is, the less total hard-
ness is permissible, e.g. buffer tank fitted, boiler
cascade, etc.).
- Boiler output (the bigger it is, the less total hard-
ness is permissible).
To determine the total allowable hardness for the
system, the specific water content must be de-
termined
:
System volume
(litres)
= Spec. water content of the
system (l/kW)
Boiler output (kW)
Example: 1166
litres
= 46.64 l/kW
25 kW