Friction Expander for the Generation of Electricity (FEGE)

Abstract

Abstract. At present and in future the necessity of generating electricity using renewable resources globally is most important and clearly evident. Depending on how the scenarios are designed and disregarding fossil resources the contributions of renewable energy sources have to be increased by a factor of four to six as far as it concerns the installed capacity and the amount of electricity generated. The corresponding annual investment costs amount some hundred billion US-$ and the CO 2 emission reduction equals one Gt. In any case heat to electricity conversion systems based on biomass, geothermal and process heat recovery are expected to provide significant contributions to this objective. Besides several others the conversion technology of a Rankine Cycle Process is most suitable over a wide range of capacities notwithstanding the possibilities to applicate working fluids of non-organic or organic character. Particularly for the heat recovery from the exhaust gas of biogas operated internal combustion engines the type of a newly developed friction expander was designed, constructed, built and evaluated. Based on preceding theoretical and numerical calculations as well as constructional and experimental studies using hexane and hexamethoxydisiloxane in the project reported here saturated water steam was used as working fluid. During the experiments carried out in a special test facility the electric power of the system amounted 1.4 kW representing two thirds of the concepttual design.

Advantages of the aerodynamic performance of micro‐Tesla turbines

“…A Tesla turbine, a type of unconventional bladeless turbomachinery, was invented and patented by the famous inventor and scientist Nikola Tesla in 1913, 1 and has a high potential for the utilization of renewable energy (e.g., biomass energy waste heat recovery, 2 geothermal power generation, 3 and solar–thermal power plant 4 ), power supply and power plant for microequipment, 5 portable power unit, 5 and the small scale organic Rankine cycle (ORC) system 6,7 . The Tesla turbine consists of a stator and rotor, similar to a conventional bladed turbine, as shown in Figure 1.…”