Optimization of the Heat Output of High Temperature Fuel Cell Micro-CHP in Single Family Homes

AbstractMicro cogeneration units are a very efficient way to supply buildings with heat and electricity. In addition to conventional powered CHP units, there are also SOFC powered units. In opposition to conventional CHP their thermal efficiency is strongly dependent on the return temperature from the DHW and heating system. The efficiency is invers to the return temperature, hence this temperature should be lowered to a minimum. Therefore a new DHW and heating system was designed. To quantify the effects a SFH supplied by a high temperature fuel cell was simulated using a standard DHW and heating system as well as an optimized one. The results show that the heat energy output and thus the thermal efficiency of the fuel cell can be increased significantly. However the annual costs also slightly increased due to the extra equipment for the new system. The optimum for energy efficiency and costs is the standard system where the storage temperature has been lowered to the minimum