In this study, an experimental investigation of the
performance a helical coil heat exchanger operating at sub- and
supercritical conditions was carried out. The heat exchanger
was coupled and tested in a small-scale Organic Rankine Cycle
installation with a net cycle capacity of 3 kW and with a heat
source inlet temperature of 100 °C. The first measurements
were conducted under controlled conditions in a laboratory.
Towards determining the effects of different parameters on the
heat transfer rate in the heat exchanger several set of
measurements were conducted. Particularly, the performance
analysis are elaborated considering the changes of various
parameters such as the mass flow rate, inlet temperature and
operating pressure of the organic (working) fluid (R-404A) at
the cold side. While all the parameters at the inlet of the hot
side were kept stable for all set of measurements. From the
experimental results and the performance evaluation of the heat
exchanger it was found that a better performance is achieved
when operating at supercritical state.
Papers presented to the 12th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, Costa de Sol, Spain on 11-13 July 2016.