Flue gas condensing at biofuel fired district heating plants
- VTT Energy, Jyvaskyla (Finland)
Water is introduced into a boiler with fuel moisture, humidity in combustion air and from combustion of fuel hydrogen. In the combustion chamber evaporation of water uses energy and lowers the combustion temperature. It is called the heat of vaporisation. Reverse process, condensation of water vapour gives back the same amount of energy. Water vapour in flue gases begins to condensate when the temperature reaches the dew point. For example in wood and peat combustion the dew point of flue gases is about 60 - 70{degrees}C. Heat of condensation is transfered to the district heating circulation using heat exchangers. An increase of 19 - 21 % to the boiler heat output at Virrat heating plant and 24% at Saarijarvi plant was achieved by flue gas condensation. This resulted in overall efficiency of 106.2 - 108.6 % at Virrat and 107.5 - 107.7% (based on LHV). Flue gas scrubbing and neutralisation resulted in 87 - 94% and 31 - 37 % sulphur reduction respectively. Reduction of particulate emissions at Virrat plant was 89 - 98%. The Saarijarvi plant has ESP, so the emissions are very low (< 6 mg/Nm{sup 3}) already before the scrubber.
- OSTI ID:
- 478642
- Report Number(s):
- CONF-960958-; TRN: 97:002640-0033
- Resource Relation:
- Conference: Partnerships to develop and apply biomass technologies, Nashville, TN (United States), 15-19 Sep 1996; Other Information: PBD: 1996; Related Information: Is Part Of Bioenergy `96: Partnerships to develop and apply biomass technologies. Volume I and II; PB: 1171 p.
- Country of Publication:
- United States
- Language:
- English
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