Exergetic Evaluation of Heat Exchanger with Multiple Inserts for Greenhouse Heating

Abstract

The heat exchanger performance is vital for attaining higher overall performance of the greenhouse heating system. The exergetic performance is evaluated for the heat exchanger using twisted tape inserts for greenhouse heating. Single, a set of two, and four twisted tapes of TR 2.5-3.5 are considered for the analysis by varying Reynolds number (Re) from 3000 to 15000. A set of two twisted tapes causes a decrease in total entropy generation up to Re of 7650 and increases beyond this value. The maximum and minimum values of the Bejan number are obtained for the smooth tube and the tube with twisted tapes (four) in “counter-swirl” orientation, respectively. The twisted tapes are feasible under the Reynolds number of 9042 based on the analysis of the entropy generation number. The minimum value of total entropy generation is obtained as 0.00035 for the four twisted tapes in counter-swirl orientation (FTT-COUS). The maximum exergy efficiency is observed for a twisted tape insert at a pitch ratio of 3.5.

Keywords

• Twisted tapes
• Twist ratio
• Entropy generation
• Exergy
• Reynolds number

References

1. M. S. Ahamed, H. Guo, and K. Tanino, “Energy saving techniques for reducing the heating cost of conventional greenhouses,” Biosystems Engineering, vol. 178, pp. 9–33, 2019, doi: 10.1016/j.biosystemseng.2018.10.017.
2. A. S. Anifantis, A. Colantoni, and S. Pascuzzi, “Thermal energy assessment of a small scale photovoltaic, hydrogen and geothermal stand-alone system for greenhouse heating,” Renewable Energy, vol. 103, pp. 115–127, 2017, doi: 10.1016/j.renene.2016.11.031.
3. I. Attar and A. Farhat, “Efficiency evaluation of a solar water heating system applied to the greenhouse climate,” Solar Energy, vol. 119, pp. 212–224, 2015, doi: 10.1016/j.solener.2015.06.040.
4. S. Agrebi, R. Chargui, B. Tashtoush, and A. A. Guizani, “Comparative performance analysis of a solar assisted heat pump for greenhouse heating in Tunisia,” International Journal of Refrigeration, vol. 131, pp. 547–558, 2021, doi: 10.1016/j.ijrefrig.2021.06.004.
5. I. Ihoume, R. Tadili, N. Arbaoui, A. Bazgaou, A. Idrissi, M. Benchrifa, and H. Fatnassi, “Performance study of a sustainable solar heating system based on a copper coil water to air heat exchanger for greenhouse heating,” Solar Energy, vol. 232, pp. 128–138, 2022, doi: 10.1016/j.solener.2021.12.064.
6. M. Dhiman, V. P. Sethi, B. Singh, and A. Sharma, “CFD analysis of greenhouse heating using flue gas and hot water heat sink pipe networks,” Computers and Electronics in Agriculture, vol. 163, 2019, Art. no. 104853, doi: 10.1016/j.compag.2019.104853.
7. M. Khoshvaght Aliabadi, M. Tatari, and M. Salami, “Analysis on Al₂O₃/water nanofluid flow in a channel by inserting corrugated/perforated fins for solar heating heat exchangers,” Renewable Energy, vol. 115, pp. 1099–1108, 2018, doi: 10.1016/j.renene.2017.08.092.
8. H. Boughanmi, M. Lazaar, and A. Guizani, “A performance of a heat pump system connected a new conic helicoidal geothermal heat exchanger for a greenhouse heating in the north of Tunisia,” Solar Energy, vol. 171, pp. 343–353, 2018, doi: 10.1016/j.solener.2018.06.054.

9. R. Thorsen and F. Landis, “Friction and heat transfer characteristics in turbulent swirl flow subjected to large transverse temperature gradients,” Journal of Heat Transfer, vol. 90, pp. 87–97, 1968, doi: 10.1115/1.3597466.
10. A. García, J. P. Solano, P. G. Vicente, and A. Viedma, “Enhancement of laminar and transitional flow heat transfer in tubes by means of wire coil inserts,” International Journal of Heat and Mass Transfer, vol. 50, pp. 3176–3189, 2007, doi: 10.1016/j.ijheatmasstransfer.2007.01.015.
11. A. Verma, M. Kumar, and A. K. Patil, “Enhanced heat transfer and frictional losses in heat exchanger tube with modified helical coiled inserts,” Heat and Mass Transfer, vol. 54, pp. 3137–3150, 2018, doi: 10.1016/j.ijheatmasstransfer.2007.01.015.
12. Y. Wang, P. Liu, F. Shan, Z. Liu, and W. Liu, “Effect of longitudinal vortex generator on the heat transfer enhancement of a circular tube,” Applied Thermal Engineering, vol. 148, pp. 1018–1028, 2019, doi: 10.1016/j.applthermaleng.2018.11.080.
13. M. K. Abdolbaqi, W. H. Azmi, R. Mamat, N. M. Z. N. Mohamed, and G. Najafi, “Experimental investigation of turbulent heat transfer by counter and co swirl flow in a flat tube fitted with twin twisted tapes,” International Communications in Heat and Mass Transfer, vol. 75, pp. 295–302, 2016, doi: 10.1016/j.icheatmasstransfer.2016.04.021.
14. S. W. Chang, K. W. Yu, and M. H. Lu, “Heat transfers in tubes fitted with single, twin, and triple twisted tapes,” Experimental Heat Transfer, vol. 18, no. 4, pp. 279–294, 2005, doi: 10.1080/08916150500201560.
15. C. Vashistha, A. K. Patil, and M. Kumar, “Experimental investigation of heat transfer and pressure drop in a circular tube with multiple inserts,” Applied Thermal Engineering, vol. 96, pp. 117–129, 2016, doi: 10.1016/j.applthermaleng.2015.11.077.
16. A. Badji, A. Benseddik, H. Bensaha, A. Boukhelifa, and I. Hasrane, “Design, technology, and management of greenhouse: A review,” Journal of Cleaner Production, vol. 373, 2022, Art. no. 133753, doi: 10.1016/j.jclepro.2022.133753.
17. Z. Naghibi, R. Carriveau, and D. Ting, “Improving clean energy greenhouse heating with solar thermal energy storage and phase change materials,” Energy Storage, vol. 2, p. e116, 2020, doi: https://doi.org/10.1002/est2.116.
18. Y. Furkan and G. Mehmet, “Numerical energy and entropy analyses of a tube with wavy tape insert including CoFe₂O₄/water nanofluid under laminar regime,” International Journal of Heat and Fluid Flow, vol. 108, 2024, Art. no. 109447 doi: 10.1016/j.ijheatfluidflow.2024.109447.
19. E. Taskesen, M. Tekır, E. Gedik, and K. Arslan, “Numerical investigation of laminar forced convection and entropy generation of Fe₃O₄/water nanofluids in different cross sectioned channel geometries,” Journal of Thermal Engineering, vol. 7, no. 7, pp. 1752–1767, 2021, doi: 10.18186/thermal.1025984.
20. N. Ocak and K. Karabulut, “Entropy and exergy analysis in an experimental thermal system used GO–DW nanofluid having straight copper pipes with different diameters,” Journal of Engineering Thermophysics, vol. 32, pp. 637–655, 2023, doi: 10.1134/S1810232823030177.
21. P. G. Kumar, N. Thangapandian, V. S. Vigneswaran, S. Vinothkumar, B. Mouli Prasanth, and S. C. Kim, “Heat transfer, pressure drop, and exergy analyses of a shot peened tube in the tube heat exchanger using Al₂O₃ nanofluids for solar thermal applications,” Powder Technology, vol. 401, 2022, Art. no. 117299, doi: 10.1016/j.powtec.2022.117299.