Two-dimensional numerical predictions of temperature profiles and pollutants formation in a porous burner are presented and validated through their comparison with available experimental data. The burner under study integrates a heat exchanger where water is heated for household applications. The Navier-Stokes, the energy and the chemical species transport equations are solved and a multislep kinetics mechanism (77 reactions and 26 species) is employed. Thermal nonequilibrium is accounted for and the discrete ordinates method, for the case of isotropic scattering, is used. Centreline temperature predictions are in good agreement with the experimental results. Predicted CO and NO emissions are compared to experimental results for a 5 kW thermal power and several excess air ratios. The model underpredicts the CO emissions and overpredicts the NO emissions. This tendency is stronger for richer mixtures. The effects of the excess air ratio, solid conductivity, convective heat transfer coefficient and radiative properties are investigated.

Fuel cells are one of the technologies available for combined heat, cooling and power production (CHCP) systems. They offer several advantages over more conventional systems, but they still need to overcome a number of barriers until they are readily available for commercialization. At this stage, it is important to fund demonstration projects that experiment with fuel cell technology in pre-commercial situations. In this context, a CHCP system, using a high-temperature fuel cell (solid oxide fuel cells, SOFC) and an absorption chiller, was designed in order to meet the energetic demands of a hospital for electricity, cooling, heating and hot water. The hospital load profile was determined taking into consideration the hourly energy consumption for four different typical days in the year. The CHCP system was designed so that the fuel cell meets the electrical demand of the hospital and, since the SOFC did not produce enough thermal energy, a boiler was considered. The artificial thermal efficiency of the CHCP system is 68%. The investment analysis is presented and it is concluded that, at the present and at three other scenarios, the system is not financially feasible. Despite this conclusion, it is important to invest on demonstration projects to help fuel cells reach commercialization. Copyright © 2008 John Wiley & Sons, Ltd.