8
HEATING BOILERS: Astra G-50E, Astra G-80E
5. InsTallaTIon
• accUMUlaTIon TanK
These solid fuel boilers are intended to be fully loaded during the operation; the most efficient mode of their exploitation is at the
nominal or maximum heat output. It is advisable to install an accumulation tank of sufficient size in their proximity, which could
accumulate the excessive heat. If the boiler is operated without the accumulation tank, its lifetime can be shortened because, in
such a case, a relatively low temperature of the outflowing water is maintained in the boiler (65-70°C). Therefore, the temperature
of the water returning to the boiler from the heating system is as low as 55-60°C. More water vapour condenses in the boiler at such
operating temperatures, more tar accumulates on the internal walls of the boiler and metal corrosion intensifies. When operating
the boiler with an accumulation tank, it is possible and advisable to maintain constantly maximum temperature of outflowing and
returning water, respectively 85°C and 70°C, then condensation of water vapour and metal corrosion will be significantly lower.
Recommended capacity of the accumulation tank is approximately 50 litres per 1 kW of nominal power of boiler:
boiler model
astra G-50e
astra G-80e
Required volume of the accumulation tank, litres
2500
4000
The boiler is to be operated only with an emergency cooling system installed!
• DescRIPTIon of THe eMeRGencY coolInG sYsTeM DIaGRaM
A thermostatic safety temperature limiter 95°C valve (Fig. 4)
protects the boiler form the overheating. If the water temperature
in the boiler exceeds 95°C, the valve automatically opens the flow
of cold water from the public water supply network through the
cooling serpentine, where it absorbs the excessive heat energy and
flows out into the sewage. The sensor of the valve with the external
thread ½” is screwed onto the socket on the rear wall of the boiler.
Technical data of the thermostatic safety valve are the
following: Opening temperature - 95°C; Maximum operating
temperature- 110°C; Operating pressure - 10 bar; Bulb of the
sensor - L=142 mm, external thread ½“.
The emergency cooling system protecting the
boiler from overheating cannot be used for heating
domestic water.
• DescRIPTIon of THe HoUse HeaTInG sYsTeM
scHeMe
The house heating system with an accumulation tank could be
divided functionally into two circles: heat production and heat
consumption. Both circles operate independently and interact in the accumulation tank. The heat production circle consists
of a boiler, Laddomat 21 thermostatic mixing unit with a circulation pump installed in it, expansion vessel, fittings and
accumulation tank. The intended use of this circle is to charge the accumulation tank only. To charge the tank, the boiler could
operate on its maximum heat output and outflowing water temperature 85°C. That mode of boiler operation is optimal for
the boiler and combustion process itself.
1
2
3
5
4
4 pav. Avarinio aušinimo sistemos pajungimo schema
1. Į kanalizaciją;
2. Terminis apsauginis vožtuvas;
3. Filtras;
4. Vanduo iš vandentiekio.
Slėgis 2-6 bar. Temperatūra °C;
5. Terminio apsauginio vožtuvo sensorius.
fig. 4 connection diagram of the emergency cooling system
1. To sewage; 2. Thermostatic safety temperature limiter 95°C
valve; 3. Filter; 4. Water from public water supply, pressure 2-6 bar,
temperature 12°C; 5. Sensor of the thermostatic safety temperature
limiter 95°C valve.