Preliminary Experimental Analysis of a CHP Hydromethane System

The paper reports the experimental preliminary results carried out on the internal combustion engine set in CHP mode, fueled by hydrogen and methane mixture. This engine is integrated into the hybrid system developed at the “La Sapienza” Universitary Sporting Center in Rome which is one of the energy district included into the already launched project named Smart Grid at "La Sapienza ". The CHP is powered by a hydrogen-methane mixture and the hydrogen is produced in situ by means of a 5 kWp PV plant. The acceptance test conducted with hydrogen percentages ranging from 0% - 10% has been carried out at lower output than the nominal, 45 kWe out of 60 kWe. Without engine parameters optimization, such as air excess and spark advance, was noted slight increases in efficiency with increasing hydrogen addition rate; Thus, it is recorded that the methane consumption decreases disproportionately to the hydrogen amount in the mixture because of the engine control system operating. The engine reflects the change in the fuel and tends to offset the working capacity loss through the throttle valve micro-openings which operates an increasing of volume flow. Referring to standard operating condition, CO and NOx emissions are reduced by 6.3% and 27% respectively by the use of a mixture of 10% hydrogen and having run the engine with 18 degrees spark advance and air index λ of 1.4. With the completion of flue gas analysis system installation, ever envisaged in the project, will be possible to repeat the performance tests, run the optimization and provide data on the energy efficiency and CO2 emission levels, in order to evaluate the environmental cost supported by comparing burdens resulting from environmental voluntary certification scheme.