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High efficiency CompactGas
steel shell boilers from Hoval
Hoval’s new CompactGas welded steel LTHW boiler is the first non-condensing
boiler to incorporate the company’s internationally patented aluFer® heat
exchanger technology to maximise heat exchange efficiencies. As such, CompactGas
closes the gap between conventional and condensing boiler technologies, making
it an ideal back-up to biomass and other low carbon heating plant where
condensing boilers would not be appropriate.
CompactGas uses Hoval’s unique combustion process to produce low dwell times in
the high temperature zone of the flame. Thanks to the innovative combustion
chamber design the exhaust gases flow out of the end of the combustion chamber
directly onto the secondary heating surface to achieve optimum combustion.
Consequently, CompactGas offers significantly higher efficiencies – typically
3.5% - compared to conventional steel shell boilers. The ’complete combustion’
design also reduces NOx emissions to well below 80 mg/kwh depending on burner
selection.
CompactGas boilers are available in models from 1000kW to 2800kW and offer 96.5%
efficiency at full load (flow/return 80°C/60°C) and 97.5% efficiency at
part-load (30%), when tested to the requirements of the European Boiler
Efficiency Directive.
Technical notes
The aluFer® heat exchanger
The aluFer® heat exchanger makes full use of the high heat conductivity
of aluminium, combined with an internal finned surface that enlarges the
heat exchange surface by five times. Each aluFer® tube is subdivided by
fins into ten flow channels to create barrier layer turbulences in the
entire cross-section, thus increasing the heat transfer by avoiding a
hot laminary core flow.
Energy savings
To put CompactGas energy savings into perspective, with a 1,000kW boiler
running 2,000 hours per annum at full load with an average return
temperature of 55°C, 3.5% energy savings equate to gas savings of
7,000m3/annum and CO2 savings of 14,000kg/annum. With a 2,800kW boiler,
these savings equate to 20,000m3/annum and 40,000kg/annum respectively.