EXPERIMENTAL INVESTIGATION OF THE EFFECT OF TURBULATOR GEOMETRY ON THE THERMAL PERFORMANCE OF GAS-FIRED BOILERS
Heat Transfer Research, cilt.57, sa.9, ss.21-34, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 57 Sayı: 9
- Basım Tarihi: 2026
- Doi Numarası: 10.1615/heattransres.2026062515
- Dergi Adı: Heat Transfer Research
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC
- Sayfa Sayıları: ss.21-34
- Anahtar Kelimeler: experimental investigation, heat transfer, natural gas-fired boiler, turbulator
- İnönü Üniversitesi Adresli: Evet
Özet
In this study, the effects of using helical and twisted turbulators with different pitch lengths and Reynolds numbers on heat transfer in a natural gas-fired boiler were experimentally investigated. The turbulence intensity, flow mixing, and pressure drop parameters induced by different turbulator geometries were evaluated and compared in terms of thermal performance and energy efficiency. In the experimental system, the effects of turbulator geometry on flow and heat transfer were assessed by measuring the flue gas outlet temperature, CO₂ and O₂ concentrations, pressure differentials, and Nusselt number. The results revealed that both types of turbulators enhanced heat transfer; however, the helical turbulator provided higher thermal performance than the twisted type by generating stronger vortices and secondary flows within the fluid. The twisted turbulator, on the other hand, maintained lower flow resistance while offering a moderate improvement in heat transfer. The findings demonstrated that turbulator design plays a decisive role in the efficiency of heat exchangers and that geometric optimization is critical for maximizing heat transfer while minimizing pressure losses. An increase in Reynolds number enhanced turbulence intensity in the flow, thereby improving heat transfer but also increasing pressure losses. In the experiments conducted at Reynolds numbers of 17,100 and 31,700, the use of a twisted turbulator resulted in Nusselt number enhancements of 36.6% and 67.3%, respectively, compared to the smooth channel, while the helical turbulator achieved increases of 147% and 163%, respectively. Overall, the study concludes that helical turbulators possess a higher heat transfer capacity than twisted ones, albeit with a corresponding rise in pressure losses. The findings highlight the practical application potential in the context of natural gas-fired boilers and clearly demonstrate the design trade-off between improved heat transfer and the accompanying pressure loss.