Abstract: The absorption power generation cycle based on the
ammonia-water mixture has attracted much attention for efficient
recovery of low-grade energy sources. In this paper a thermodynamic
performance analysis is carried out for a Kalina cycle using
ammonia-water mixture as a working fluid for efficient conversion of
low-temperature heat source in the form of sensible energy. The
effects of the source temperature on the system performance are
extensively investigated by using the thermodynamic models. The
results show that the source temperature as well as the ammonia mass
fraction affects greatly on the thermodynamic performance of the
cycle.
Abstract: ORC (Organic Rankine Cycle) has potential of
reducing consumption of fossil fuels and has many favorable
characteristics to exploit low-temperature heat sources. In this work
thermodynamic performance of ORC with regeneration is
comparatively assessed for various working fluids. Special attention is
paid to the effects of system parameters such as the turbine inlet
pressure on the characteristics of the system such as net work
production, heat input, volumetric flow rate per 1 MW of net work and
quality of the working fluid at turbine exit as well as thermal
efficiency. Results show that for a given source the thermal efficiency
generally increases with increasing of the turbine inlet pressure
however has optimal condition for working fluids of low critical
pressure such as iso-pentane or n-pentane.