Low- and medium-temperature deep geothermal energy is utilized in various countries for combined heat and power generation (CHP). In addition, due to the heat island effect and the higher requirements about thermal wellbeing, the cooling demand is expected to significantly increase within the future. In contrast to electricity-intensive vapour compression cycles, absorption chillers driven by geothermal energy are a promising environmentally friendly alternative for cooling purposes. Therefore, geothermal trigeneration systems that can provide cooling, heating and power generation by an Organic Rankine Cycle (ORC) will be of high interest in the future. While there is a strong research focus on advanced ORC CHP concepts for geothermal applications, the investigation of efficient and flexible geothermal trigeneration systems is still at an early stage and so far only a few potential concepts were evaluated. In addition, most of the existing studies consider only rather simple ORC models and neglect the part-load behaviour due to changing cooling and heating demands. This paper evaluates the performance of several trigeneration arrangements. A special focus is laid on different plant architectures and their part-load behaviour as well as the optimal integration of different absorption chiller types. The results provide valuable insights on the most promising trigeneration system concepts for different geothermal heat source temperatures and demand profiles. For assumed heat source conditions of 130 kg/s and 130 °C, the results reveal that an advanced serialparallel configuration provides the highest net power output over the year, followed by a serial configuration with the absorption chiller on the third position and a standard serial-parallel configuration. Considering the part-load behaviour and the optimal absorption chiller integration can have a significant impact on the achievable plant power output. Thus, a meaningful comparison of different systems with varying heating and cooling demands requires the consideration of both the absorption chiller integration and the part-load behavior.     «

Low- and medium-temperature deep geothermal energy is utilized in various countries for combined heat and power generation (CHP). In addition, due to the heat island effect and the higher requirements about thermal wellbeing, the cooling demand is expected to significantly increase within the future. In contrast to electricity-intensive vapour compression cycles, absorption chillers driven by geothermal energy are a promising environmentally friendly alternative for cooling purposes. Th...     »