Dynamic simulation of a microcogeneration system experimentally validated in a test facility in Spain

The diffusion of micro-cogeneration systems can significantly contribute to reduction of primary energy consumption and greenhouse gas emission attributed to the residential sector, if compared with the conventional separate energy conversion systems.The paper analyses a microcogeneration system used to satisfy electric and thermal demand (space heating and domestic hot water) of two semi-detached houses. It consists of a reciprocating internal combustion engine fuelled by natural gas, with a thermal and electric power of 12.5 kW and 5.5 kW, respectively. A high efficiency auxiliary boiler with a nominal thermal power of 24 kW, is included to supply heat when microgeneration unit capacity is not enough to meet the heating load. A load sharing approach between the two residential building is taken into account. The domestic hot water and the heating requests are managed by means of two different thermal storages. In order to analyse the influence of climatic conditions and to make the results more general for different geographical areas, two different locations one in Italy and one in Spain, are considered,.The models representing the components, and the buildings have been implemented in a widely used commercial software for building simulations.The models were calibrated and validated through data obtained from experimental tests carried out in the test facility at Laboratory for the Quality Control in Buildings LCCE (Vitoria-Gasteiz, Spain). The results of the simulations highlight the potential benefits of the load sharing approach. In particular, this study shows that the proposed system can obtain an interesting primary energy saving and reduction in terms of equivalent CO2 emissions with respect to an appropriate reference system, both in Spain and Italy.