| Title | DESIGN OF PENTANE VAPORIZERS – A CFD APPROACH |
|---|---|
| Authors | S. Siwach, M. Jermy, M. Sellier |
| Year | 2015 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | ORC, Heat Exchangers, Bubble Dynamics, Pentane Vaporizer, CFD |
| Abstract | Heat Exchangers (HEs) transfer heat energy from the source to the motive fluid, are a major component of the installation and maintenance costs and have a significant bearing on performance and efficiency of the plant. HEs are usually designed conservatively due to lack of detailed predictive models. Optimised designs can lead to reduced costs and increased plant efficiency. The project develops an approach for CFD analysis of single-phase and phase-change heat exchangers. CFD models have been validated against experimental data for simple geometries. For multi-tube geometries, the validation is of a qualitative nature because of a lack of experimental data. The final aim of the project is to perform the CFD analysis of a commercial pentane vaporizer (horizontal orientation) (Figure-7). The main objectives are: a) To understand the impact of liquid level on the heat transfer performance of the Vaporizer b) To know the probability of droplets being carried into the superheater by the hot vapor flow At the current stage – a) single-phase CFD models have been validated, b) multi-phase models (which need to be tuned on a case-by-case basis) have been validated for single-tube geometries. Lack of experimental data for pentane boiling has necessitated selection of a surrogate fluid to validate model set-up which has been done on the basis of thermophysical properties and dimensionless numbers that characterize the boiling phenomenon, viz. bubble Reynolds number, Morton number, Eotvos number, Weber number, Boiling number and Jakob number. |