Advanced ORC architecture for geothermal combined heat and power generation

Several approaches to enhance the performance of Organic Rankine Cycles (ORC) have been investigatedin literature, including architecture, workingfluid selection and part-load optimization together withcombined heat and power (CHP) generation. To contribute to these developments, the design and thefirst operation of an advanced ORC-CHP architecture is being presented in this study. This architectureextends the state of the art by a two-stage concept with turbine bleeding and a regenerative directcontact preheater. The aim of this architecture is to increase the heat source utilization,flexibility andpart-load efficiency. To evaluate the performance of this concept, a test rig has been constructed. It isheated with a 200 kW electrical heater and a twin-screw expander is being used. The low-GWPfluidR1233zd(E) is applied as workingfluid. In order to analyze the system in its full operating range, ex-periments are conducted with varying heat loads of the district heating network. Furthermore, anoperating strategy of the system is being developed. With thisfirst operation, a very high operationalrange of the novel ORC-CHP architecture down to a minimum load of 15.3% is being demonstrated.Furthermore, is could be proven that thermal efficiency increases during part-load operation.     «

Several approaches to enhance the performance of Organic Rankine Cycles (ORC) have been investigatedin literature, including architecture, workingfluid selection and part-load optimization together withcombined heat and power (CHP) generation. To contribute to these developments, the design and thefirst operation of an advanced ORC-CHP architecture is being presented in this study. This architectureextends the state of the art by a two-stage concept with turbine bleeding and a regenerative direc...     »