INVESTIGATION OF ENTROPY GENERATION AND EXERGY GAIN OF GO-WATER NANOFLUID DEPENDING ON WORKING CONDITIONS
DOI:
https://doi.org/10.5281/zenodo.8198595Keywords:
Entropy generation; Exergy gain,; GO-Water nanofluid;2nd law efficiencyAbstract
Entropy and exergy analysis of a thermal system is one of the most powerful tools that can be used to determine the optimum operating conditions of the system. While exergy is a measure of usability; entropy production in the system reduces the usability, that is, the exergy. Therefore, entropy and exergy are two opposite phenomena and they must be kept under control in order for the system to operate with high efficiency. In this study, entropy generation and exergy gain analysis of an experimental thermal system consisting of a copper straight pipe with a constant heat load, 12 mm inner diameter and 1830 mm length using GO (Graphene Oxide)-Water nanofluid was performed. While the heat loads applied to the copper pipe were 250 W and 350 W, the flow rates of the fluids flowing in the pipe were 0.9 l/min., 1.2 l/min., 1.5 l/min. and 1.8 l/min. GO-Water nanofluid with 0.01% and 0.02% volumetric concentrations and distilled water were used as working fluids in the system. The results obtained from this study were compared with the studies conducted with different nanofluids in the literature and it was determined that the results were reasonable and consistent. As variable parameters in the study; nanofluid concentration, fluid flow rate and thermal load applied to the pipe were used. The results of the study were evaluated in detail as the variations of thermal and friction entropy generation, output exergy and the 2nd law efficiency along the length of the 12 mm inner diameter copper pipe, and the most suitable working conditions were determined. The results showed a 93.43% reduction in entropy production at an average of 0.02% GO-Water nanofluid concentration along the pipe at 250 W heat load and 0.9 l/min flow rate compared to 0.01% GO-Water nanofluid concentration. In addition, the exergy of 0.01% GO-Water nanofluid is 58% higher at a flow rate of 1.8 l/min compared to a flow rate of 0.9 l/min; it has determined that 2nd law efficiency of the nanofluid is 7.15% higher than the flow rate value of 0.9 l/min at a flow rate of 1.8 l/min.
References
Ahammed, N., Asirvatham, L.G., Wongwises, S. (2016). Entropy generation analysis of graphene-alumina hybrid nanofluid in multiport minichannel heat exchanger coupled with thermoelectric cooler. Int J Heat Mass Transfer, 103: 1084-1097.
Bejan, A. (1979). A study of entropy generation in fundamental convective heat transfer. J Heat Transfer, 101: 718-725.
Bejan, A. (1996). Entropy generation minimization, the method of thermodynamic optimization of finite-size systems and finite-time processes, J Appl Phys., 79: 1191.
Godson, L., Raja, B., Lal, D.M., Wongwises, S. (2010). Enhancement of heat transfer using nanofluids-an overview. Renew Sust Energy Rev., 14: 629-641.
Goudarzi, N., Talebi, S. (2015). Improving performance of two-phase natural circulation loops by reducing of entropy generation. Energy, 93: 882-899.
Hajjar, Z., Rashidi, A., Ghozatloo, A. (2014). Enhanced thermal conductivities of graphene oxide nanofluids. Int Comm Int Heat and Mass Trans., 57: 128-131.
Herwig, H., Wenterodt, T. (2011). Second law analysis of momentum and heat transfer in unit operations. Int J Heat Mass Transfer, 54: 1323-1330.
Hummers, W.S., Offeman, R.E. (1958). Preparation of graphitic oxide. J Am Chem Soc., 80: 1339.
Hussien, A.A., Abdullah, M.Z., Yusop, N. Md., Al-Kouz, W., Mahmoudi, E., Mehrali, M. (2019). Heat transfer and entropy generation abilities of MWCNTs/GNPs hybrid nanofluids in microtubes. Entropy, 21: 480.
Ji, Y., Zhang, H.C., Tong, J.F., Wang, X.W., Wang, H., Zhang, Y.N. (2016). Entropy assessment on direct contact condensation of subsonic steam jets in a water tank through numerical investigation. Entropy, 18: 21.
Ji, Y., Zhang, H.C., Yang Shi, L. (2017). Entropy generation analysis and performance evaluation of turbulent forced convective heat transfer to nanofluids. Entropy, 19: 108.
Karami, M., Shirani, E., Avara, A. (2012). Analysis of entropy generation, pumping power and tube wall temperature in aqueous suspensions of alumina particles. Heat Transfer Res, 43: 327-342.
Keklikcioğlu, O. (2021). Entropy generation analysis of a heat exchanger tube with graphene-ıron oxide hybrid nanofluid. Eur J Sci Tech., 24: 398-404.
Khalkhali, H., Faghri, A., Zuo, Z.J. (1999). Entropy generation in a heat pipe system. Appl Therm Eng., 19: 1027-1043.
Khaleduzzaman, S.S., Sohel, M.R., Saidur, R., Mahbubul, I.M., Shahrul, I.M., Akash, B.A., Selvaraj, J. (2014). Energy and exergy analysis of alumina–water nanofluid for an electronic liquid cooling system. Int Commun Heat Mass Transfer, 57: 118-127.
Khaleduzzaman, S.S., Sohel, M.R., Mahbubul, I.M., Saidur, R., Selvaraj, J. (2016). Exergy and entropy generation analysis of TiO2-Water nanofluid flow through the water block as an electronic device. Int. J. Heat Mass Transfer, 101: 104-111.
Korei, Z., Benissaad, S. (2021). Turbulent forced convection and entropy analysis of a nanofluid through a 3D 90° elbow using a two‐phase approach. Heat Transfer, 50: 1-31.
Leong, K.Y., Saidur, R., Mahlia, T.M.I., Yau, Y.H. (2012). Entropy generation analysis of nanofluid flow in a circular tube subjected to constant wall temperature. Int Commun Heat Mass Transfer, 39: 1169-1175.
Mahmud, S., Fraser, R.A. (2002). Thermodynamic analysis of flow and heat transfer inside channel with two parallel plates. Exergy An Int J., 2: 140-146.
Mahmud, S., Fraser, R.A. (2003). The second law analysis in fundamental convective heat transfer problems. Int J Thermal Sci., 42: 177-186.
Mehrali, M., Sadeghinezhad, E., Rosen, M.A., Akhiani, A.R., Latibari, S.T., Mehrali, M., Cornelis Metselaar, H.S. (2015). Heat transfer and entropy generation for laminar forced convection flow of graphene nanoplatelets nanofluids in a horizontal tube. Int Comm Heat and Mass Transfer, 66: 23-31.
Moghaddami, M., Shahidi, S., Siavashi, M. (2012). Entropy generation analysis of nanofluid flow in turbulent and laminar regimes. J Comput Theor Nanosci, 9: 1586-1595.
Myat, A., Thu, K., Kim, Y.D., Chakraborty, A., Chun, W., Ng, K.C. (2011). A second law analysis and entropy generation minimization of an absorption chiller. Appl Therm Eng., 31: 2405-2413.
Narendran, G., Bhat Mithilesh, M., Akshay, L., Arumuga Perumal, D. (2018). Experimental analysis on exergy studies of flow through a minichannel using TiO2/Water nanofluids. Therm Sci Eng Prog., 8: 93-104.
Novoselov, K., Geim, A.K., Morozov, S., Jiang, D., Grigorieva, M.K.I., Dubonos, S., Firsov, A. (2005). Two-dimensional gas of massless dirac fermions in graphene. Nature, 438: 197-200.
Pak, B.C., Cho, Y.I. (1998). Hydrodynamic and heat transfer study of dispersed fluids with submicron metallic oxide particles. Experimental Heat Transfer, 11: 151-170.
Pandey, S.D., Nem, V.K. (2012). Experimental analysis of heat transfer and friction factor of nanofluid as a coolant in a corrugated plate heat exchanger. Exp Therm Fluid Sci., 38: 248-256.
Saidur, R., Leong, K.Y., Mohammad, H.A. (2011). A review on applications and challenges of nanofluids. Renew Sust Energy Rev., 15: 1646-1668.
Schmandt, B., Herwig, H. (2011). Loss coefficients in laminar flows: essential for the design of micro flow systems. PAMM, 11: 27-30.
Singh, P.K., Anoop, K.B., Sundararajan, T., Das, S.K. (2010). Entropy generation due to flow and heat transfer in nanofluids. Int J Heat Mass Transfer, 53: 4757-4767.
Szargut, J., Morri, D.R., Steward, F.R. (1988). Exergy analysis of thermal, chemical and metallurgical processes. Hemisphere Pubs., New York, USA.
Taskesen, E., Tekir, M., Gedik, E., Arslan, K. (2021). Numerical ınvestigation of laminar forced convection and entropy generation of Fe3O4/water nanofluids in different cross-sectioned channel geometries. J Therm Eng., 7: 1752-1767.
Yu, W., Xie, H., Chen, L., Li, Y. (2010). Enhancement of thermal conductivity of kerosene-based Fe3O4 nanofluids prepared via phase-transfer method. Colloids and Surfaces A, 355: 109-113.
Wen, D., Lin, G., Vafaei, S., Zhang, K. (2009). Review of nanofluids for heat transfer applications. Particuology, 7: 141-150.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2023 EJONS INTERNATIONAL JOURNAL
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
