A new high temperature fuel cell-micro gas turbine physical emulator has been designed and installed in the framework of the European Integrated Project “FELICITAS” at the Thermochemical Power Group (TPG) laboratory located at Savona. The test rig is based on a commercial 100 kWe recuperated micro gas turbine (mGT) (Turbec T100) modified to be connected to a modular volume designed for physical emulation of fuel cell stack influence. The test rig has been developed starting with a complete theoretical analysis of the micro gas turbine design and off-design performance and with the definition of the more flexible layout to be used for different hybrid system (molten carbonate fuel cell or solid oxide fuel cell) emulation. The layout of the system (connecting pipes, valves, and instrumentation, in particular mass flow meter locations) has been carefully designed, and is presented in detail in this paper. Particular attention has been focused on the viscous pressure loss minimization: (i) to reduce the unbalance between compressor and expander, (ii) to maintain a high measurement precision, and (iii) to have an effective plant flexibility. Moreover, the volume used to emulate the cell stack has been designed to be strongly modular (different from a similar system developed by U.S. Department Of Energy-National Energy Technology Laboratory) to allow different volume size influence on the mGT rig to be easily tested. The modular high temperature volume has been designed using a computational fluid dynamics (CFD) commercial tool (FLUENT). The CFD analysis was used (i) to reach a high level of uniformity in the flow distribution inside the volume, (ii) to have a velocity field (m/s) similar to the one existing inside the emulated cell stack, and (iii) to minimize (as possible) the pressure losses. The volume insulation will also allow to consider a strong thermal capacity effect during the tests. This paper reports the experimental results of several tests carried out on the rig (using the mGT at electrical stand-alone conditions with the machine control system operating at constant rotational speed) at different load values and at both steady-state and transient conditions

Abstract:The increasing interest in small-scale renewable-energy plants for distributed power generation has led to a demand for suitable software tools to study and develop control systems able to manage advanced integrated systems. Biomass, as a renewable energy resource, needs to be processed if it is to be exploited in small CHP units and pyrolysis is one of the options available for transforming solid biomass into useful liquid and gaseous fuels. This work is concerned with the development of a time-dependent model of a rotary-kiln pyrolyser for biomass: the model is intended for the development of control systems and the simulation of integrated energy systems, where the pyrolyser is connected to a power-generation package. The model was developed within the TRANSEO environment and based on a quasi 2-D numerical discretisation of the rotary kiln. Results are shown for a real case that is currently under construction: the model is able to predict the impact of different operating conditions on fuel yields, as well as capturing the main transient phenomena occurring during changes in the pyrolyser operating conditions.