6
Tab. č. 2 Thermal – technical parameters
Reference conditions 15°C a 1013,25 mbar, dry gas
Output for CH [kW] 8 – 24
Output for HSW [kW] 8 – 24
Fuel volume flow [m3.h-1] 0,9 – 2,7
Mass rate of flue gases min./max. [g.s-1] 21,9/30,9
HSW flow ∆T 25°C [l.min-1] 13
HSW flow ∆T 35°C [l.min-1] 9
CH outlet temperature regulation [°C] 30-85
HSW outlet temperature regulation [°C] 30-60
Efficiency [%] 90-92
CO [ppm] 7-14
NOx [ppm] 20-50
Combustion gases temperature [°C] 130°C
4. Boiler description
4.1. Boiler construction
VIADRUS CLEO wall boiler with water flow heating is equipped with a copper heat exchanger the whole
surface of which is protected by a silicone paint based on aluminium with a resistance up to 350°C. These
exchangers have separated systems for HSW heating and the heating system. A big advantage of the heat
exchangers is that they save space and weight. The maximum working pressure for CH circuit is 3 bar at the
working temperature of 85 °C and 6 bar for HSW preparation at the working temperature of 85 °C. Minimum
working pressure is 1bar. The heat exchanger is positioned in the upper part of the combustion chamber an
automatic bleeder valve is mounted on it, a part of which ends above the combustion chamber. Due to the
minimum loss caused by the thermal transmission it is necessary to keep the surface of heat exchanger
lamellae clean.
The gas burner has an advanced modular construction and is made of stainless steel. It is positioned in the
lower part of combustion chamber and electrodes are mounted on it, where one of them is the ignition electrode
and another one is the ionisation electrode. The combustion chamber is made of aluminised steel plate with an
internal thermal insulation. Above the combustion chamber (in VIADRUS CLEO T design) there is positioned
the flue gases collector on which there is mounted a flue gases outlet ventilator. This ventilator by means of
silicon hoses is connected to the differential pressure switch ( manostat ). In VIADRUS CLEO K design above
the combustion chamber there is installed the draught diverter on which there is mounted the flue gases
thermostat (surface sensor).
In the upper part of the heat exchanger there are installed the thermal sensors for heating system and HSW.
The internal water circuit in the boiler is made of copper tubes. The closing chamber at VIADRUS CLEO T
design is made of aluminised sheet. The openings in this closing chamber are sealed by means of silicone
bushings. On HSW inlet there is installed the water flow sensor.
This boiler in both designs is equipped with automatic and gradual output control. The main control
element of this boiler is the modular electronic board equipped with a microprocessor which evaluates the
conditions and values of sensors and issues the commands to the gas valve , ignition electronics and circulation
