Title:
Numerical and Experimental Performance Study on a Diaphragm Expander for Application in Small Scale Organic Rankine Cycles
Author(s):
Carow, J.R., Link, T., Rathje, R.M.
Document(s):
Paper
Poster
Abstract:
In contrast to other types of expanders, so far little attention has been given to diaphragm expanders. This type of expander contains a diaphragm which seals the cylinder and prevents leakage of working fluid through this part. Piston displacement is relatively small while inlet and outlet have a rather large diameter, further reducing potential losses during charge and discharge phase. The fluid flow is controlled by a rotary slide valve. Production costs are low since the expander requires only low-priced parts. The working fluid is the cooling agent R245fa, with a design expansion volume ratio set to 3.5. This study describes fundamental investigation and redesign of a diaphragm expander for use in small-scale Organic Rankine cycles (ORC). A numerical model based on fully-coupled fluid-structure interaction (FSI) was created and then reduced to a simpler Computational Fluid Dynamics model (CFD) in order to achieve shorter computation times. Results from numerical studies on expander performance were directly compared with results from experimental measurements and then used to summarize the expander’s characteristics.
Keywords:
efficiency, modelling, organic rankine cycle (ORC), power generation, small scale application
Topic:
Biomass Conversion Technologies for Heating, Cooling and Electricity
Subtopic:
Biomass and bioliquids combustion for small and medium scale applications
Event:
23rd European Biomass Conference and Exhibition
Session:
2BV.2.31
Pages:
716 - 720
ISBN:
978-88-89407-516
Paper DOI:
10.5071/23rdEUBCE2015-2BV.2.31
Price:
FREE
