Evaluation of CCHP systems fuelled by mixture of biogas and LPG based on different thermally activated chillers.

A biomass fuelled CCHP system with fossil fuel supplement can be more reliable and flexible. In this work, the influence of different mixture ratios of biogas and liquefied petroleum gas (LPG) on the waste heat output of internal combustion engine (ICE) is studied. Based on the waste heat output, three different thermally activated chillers such as single effect absorption chiller, mixed effect absorption chiller and adsorption chiller are investigated. An experiment is conducted to study the generation of biogas through biomass gasification and to test the composition of biogas. By modeling ICE, the quantity of waste heat in both exhaust gas and jacket water is calculated while mixture ratios of biogas and LPG are varying. By modeling different thermally activated chillers, the cooling capacities are obtained under different quantity of waste heat. Performance of power generation unit (PGU), thermally activated chillers as well as the whole system is analyzed accordingly.