Energy Analysis of a Biomass-Based Combined Cooling, Heating, and Power System

Combined cooling, heating, and power (CCHP) systems aim at raising systems’overall efficiency by utilizing both the electrical and thermal energy output available from energy conversion processes. An even higher advantage can be obtained by using biomass as a fuel. Integrating a CCHP system with buildings to fulfill the energy demands appears to be one of the most promising applications so far. Therefore, the scope of this study is to dynamically investigate the energy system performance and operation of a biomass-based CCHP system that satisfies the energy demands of an end-user building. In this study, an Aspen Plus model is developed for the simulation of a 100 kWe externally fired gas turbine fed by wood biomass combustion. The results from the Aspen model are used as an input to the remaining components of the CCHP system that are modeled in TRNSYS. The thermal energy recovered from the gas cycle is used to meet the user’s thermal demand. A storage tank supplies direct heat to the end-user in winter and drives an absorption chiller for cooling during summer. The model is developed to fulfill the energy needs of the historical building “Sant’Apollinare” located in Perugia, Italy. A demand model, which calculates the hourly thermal load of the building is developed in TRNSYS. The transient system is designed such that it fulfills the peak load demands of the building. Subsequently, the model provides data on performance parameters of different components such as temperature, power consumption, and energy efficiency which leads to evaluating the feasibility and the overall energy performance of the CCHP system. It is expected that besides heating and cooling the building, the thermal energy recovered has the potential to provide sufficient energy for biomass drying and/or district water heating (DWH).