Selected aspects of the design and operation of the first Polish residential micro–CHP unit based on solid oxide fuel cells

摘要

The first Polish micro-combined heat and power unit (micro-CHP) with solid oxide fuel cells (SOFC) was designed and constructedin the facilities of the Institute of Power Engineering in Warsaw. The system was launched in September 2015 andis under investigation. At the current stage the unit is customized to operate on a pre-treated biogas. Adaptation of the fuelprocessing system, which is based on a steam reformer, makes it possible to utilize other gaseous and liquid fuels, includingnatural gas. The electric and thermal output of the system, up to 2 kW and about 2 kW, respectively, corresponds to the typicalrequirements of a detached dwelling or a small commercial site. Functionality of the system was increased by engaging twoseparate start-up modules, which are used for preheating the system from a cold state to the nominal working conditions.The first module is based on a set of electric heaters, while the second module relies on an additional start-up burner. Thestartup of the system from ambient conditions up to a thermally self-sufficient stage takes about 7 hours using the electricpreheaters mode. Output residual heat was used to heat water to a temperature of about 50C. The temperature of the fluegases at the inlet to the hot water tank was measured at approximately 300C. Steam reforming of the biogas was performedby delivering deionized water to the steam reformer in order to maintain the S/C ratio at a range of 2 .. 3.5. Selected aspectsof the design and construction as well the first operational experiences are presented and discussed. The numerical modelingmethodology is presented as a complimentary tool for system design and optimization.