| dc.description.abstract | District heating is an optimal system of distributing heat to residential building in a centralized location through pipeline networks. The district heating of woodchip is cost effective, improve energy efficiency, reduce gas emissions and improve energy security. The thermal efficiency and energy balance in a boiler is obtained by combustion analysis of the wood (fuel). In this report, the district heating bio fuel burner in Skien Fjernvarme is considered. The capacity of the boiler is 6MW and the operation commenced in December 2012. The energy balance in a boiler is characterized by the input, output and losses from the boiler. The input components are the woodchip, feed water and combustion air. The losses increases if the woodchip is of high moisture content, more soot in the boiler tubes, woodchip degradation as a result of wood storage etc. The losses gotten from the evaporation of moisture in Skien Fjernvarme boiler is 80.4kWh/m3 from calculation analysis. This loss is a major one from the boiler. The net heat output from calculation is 722kWh/m3 for 1m3 loose woodchip. In the month of December, the woodchip supply was 2350 loose m3; the net heat production was 1698MWh (If all woodchip are utilized). January generate net heat of 2816MWh with a supply of 3900 loose m3. The net heat in February and March are 2238MWh and 2819MWh for supply of 3100 loose m3 and 3905 loose m3 respectively. The thermal efficiency of Skien Fjernvarme district heater in this report is determined from combustion and analysis of the constituents of the woodchips. The efficiency of a boiler is affected by the wood quality, feed water quality, the moisture content, excess air, density of the woodchip and the operation of the boiler. The thermal efficiency of Skien Fjernvarme district heating system from analysis calculation is 85%. This value indicates that the boiler is in good working state. | |
