Kohesi: Jurnal Sains dan Teknologi

Articles

Vol. 11 No. 3 (2026): Kohesi: Jurnal Sains dan Teknologi, ISSN 3025-1311

PERFORMANCE ANALYSIS OF A SPIRAL COIL CONDENSER USING COMPUTATIONAL FLUID DYNAMICS (CFD)-BASED NUMERICAL SIMULATION IN A SYNTHETIC FUEL PRODUCTION FACILITY

DOI:
https://doi.cibangsa.org/DOI-2026-44
Submitted
August 28, 2026
Published
2026-08-28

Abstract

The energy crisis and increasing plastic waste have encouraged the development of thermochemical conversion technologies through pyrolysis. The pyrolysis process produces hydrocarbon vapor that must be condensed into liquid fuel, making condenser performance an important factor in determining the effectiveness of the condensation process. This study aims to analyze the effect of spiral coil diameter variation with a constant number of turns on condenser performance and to determine the most optimal configuration. A numerical method based on Computational Fluid Dynamics (CFD) was employed using ANSYS Fluent. The condenser was modeled in a shell-and-spiral-coil configuration with diameter variations of 10 cm, 20 cm, and 30 cm, while the number of turns was kept constant at 10. The simulations were performed under a counter-flow configuration using pyrolysis vapor as the hot fluid and water as the cooling fluid. The analyzed performance parameters included temperature distribution, heat transfer rate, overall heat transfer coefficient, Number of Transfer Units (NTU), and condenser effectiveness. The simulation results show that increasing the spiral coil diameter reduced the pyrolysis vapor outlet temperature from 24.376 °C at a diameter of 10 cm to 22.107 °C at 20 cm and 21.902 °C at 30 cm. The heat transfer rate increased from 197.144 W to 208.155 W and 209.150 W, while the NTU increased from 2.792 to 4.682 and 5.385. Condenser effectiveness also increased from 93.82% to 99.06% and 99.53%. The overall heat transfer coefficient decreased from 74.17 W/m²·K to 51.88 W/m²·K as the spiral coil diameter increased. Based on the overall performance parameters, the 30 cm diameter with 10 turns provided the most optimal configuration under the simulated conditions. These results provide a technical basis for the development of spiral-coil condenser designs for plastic waste pyrolysis systems.

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