Study of the integration of a supersonic impulse turbine in a NH3/H2O absorption heat pump for combined cooling and power production from a low temperature heat source

Abstract

The present work is focused on the investigation of an absorption cycle integrated with an impulse axial turbine for the combined production of cooling and electric power. This technology holds great promise for its ability to harness low-temperature heat sources, more effciently in comparison to separate production with simple cycles. By developing a 1D model of the expander, and integrating it into a 0D model of the complete cycle, it is possible to evaluate the performance of the cycle and its variation with respect to the operating parameters, namely the temperature of the external resources. Pending an experimental validation of the results, this study showed the importance of correctly defining the temperature of the sources - namely the generator temperature - in order to satisfy the technological needs while also maximising the effciency of the cycle. Finally it was highlighted how the integration of a supersonic impulse turbine strongly limits the flexibility during operation given the constant mass flow rate treated by the expander.