Session 7: The Scandinavian Green Way - CHP - Energy Efficiency Session date: 11/6/2015

摘要

Combined heat and power (CHP) production is one way to utilize the fuel energy most optimized way. There are additional procedures and concepts how CHP plant efficiency and energy economics can be further improved. Heat recovery from flue gases by using flue gas condensing (FGC) technology, with or without combustion air humidifier (CAH) or heat pump (feasibility of such depends on process parameters), is a practical solution to increase district heating (DH) capacity. Technology can be installed in an existing power plant or to a green field plant in order to further optimize the whole CHP plant solution. Naturally flue gas condensers decrease emissions, and different design aspects and targets can be taken into account in design. This paper will introduce the main technological variations of flue gas condensers and also practical experiences of two selected cases. The first case is a power plant (boiler size 69 MWth) in Southern Finland and it has been in operation since early 2012. A tube type flue gas condenser and a combustion air humidifier were built together with the power plant. Last year further optimization for flue gas condensing operating principles were done, and that has yielded promising results. The second case is a power plant (boiler size 73 MWth) also in Finland and it has been in operation since 1995. A scrubber type flue gas condenser and a combustion air humidifier were retrofitted to an existing plant in autumn 2014. Installation was executed in 9 months and it required no extra downtime for boiler.