Over the last years, the optimization of the Organic Rankine Cycle technology has been enforced. There are several approaches to increase the efficiency of ORC plants, including the ORC plant design, the working fluid selection, the part-load optimization together with combined heat and power (CHP) generation, as well as the optimization of the plant components. In order to contribute to these optimization measures, the design and first operation of an advanced ORC-CHP plant architecture optimized for geothermal applications, is presented in this study. This architecture extends the state of the art ORC by a two-stage expander with turbine bleeding and a regenerative direct contact preheater. The aim of this architecture is to increase the utilization of the heat source, the flexibility and the part-load efficiency of the plant. In order to evaluate the performance of this ORC-CHP concept, a test rig has been constructed. The test rig is heated with a 200 kW electrical resistance heater, which is controlled by pulse width modulation. As expander, a twin screw compressor is used, which operates in reverse mode and R1233zd(E) is applied as working fluid. Besides an in-depth description of the test rig, the system is analyzed in its complete operational range. Therefore, experiments are conducted with varying heat loads of the district heating network. With this, an operation strategy of the ORC system for the full operational range is derived.     «

Over the last years, the optimization of the Organic Rankine Cycle technology has been enforced. There are several approaches to increase the efficiency of ORC plants, including the ORC plant design, the working fluid selection, the part-load optimization together with combined heat and power (CHP) generation, as well as the optimization of the plant components. In order to contribute to these optimization measures, the design and first operation of an advanced ORC-CHP plant architecture optimiz...     »