Thermodynamic analysis of a tunnel biscuit oven and heat recovery system
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Abstract
Biscuit baking ovens are produced as tunnel type to reduce the cost of final product and increase the production capacity. Tunnel type ovens are designed in the form of conveyor and wire mesh or steel belt is used as a carrier element according to the biscuit type. In tunnel type biscuit ovens, the product that enters as dough from one end of the tunnel comes out as a baked product from the other end of the tunnel. In this study 1.2 m belt width and 61.5 m long tunnel oven which has 1850 kg/h Petit Beurre biscuit production capacity is analyzed. Working parameters of this tunnel oven taken into account for calculations. Natural gas is used to generate heat for baking and during baking high amount of energy released to the atmosphere with exhaust gas and water evaporated from biscuit dough. In this study, the energy and exergy analysis of the system made by taking into account the properties of flue gas discharged from industrial type biscuit oven. Flue gas released from chimney to the atmosphere is 503.15 K which could be used to generate electricity with Organic Rankine Cycle. The data obtained as a result of this study can be used to optimize the energy required to produce unit product. As a result of energy and exergy analysis of the system, 58.62 kW of power could be generated by Organic Rankine Cycle by using waste flue gas. It has been observed that energy efficiency of the oven increased from 3.90% to 11.04% and exergy efficiency of the oven increased from 0.5% to 6.22% by generating electricity with Organic Rankine Cycle.
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References
Davidson, I. (2023). Biscuit baking technology: Processing and engineering manual (2nd ed.). Elsevier.
Manley, D. (2000). Technology of biscuits, crackers, and cookies (3rd ed.). Woodhead Publishing.
Broyart, B., & Trystram, G. (2003). Modelling of heat and mass transfer phenomena and quality changes during continuous biscuit baking using both deductive and inductive (neural network) modelling principles. Food and Bioproducts Processing, 81(4), 316-326. https://doi.org/10.1205/096030803322756402
Baik, O. D., Marcotte, M., & Castaigne, F. (2000). Cake baking in tunnel type multi-zone industrial ovens Part I. Characterization of baking conditions. Food Research International, 33(7), 587-598. https://doi.org/10.1016/S0963-9969(00)00095-8
Mirade, P. S., Daudin, J. D., Ducept, F., Trystram, G., & Clement, J. (2004). Characterization and CFD modelling of air temperature and velocity profiles in an industrial biscuit baking tunnel oven. Food Research International, 37(10), 1031-1039. https://doi.org/10.1016/j.foodres.2004.07.001
Protopopov, E. A., Dobrykh, S. S., & Protopopov, A. A. (2018). Estimation of temperature dependences of specific heat capacity of low-alloy steels. International Journal of Applied Engineering Research, 13(18), 13536-13540.
ASHRAE. (2010). Handbook of refrigeration: Thermal properties of foods. American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc.
Tesisat.org. (2022, January 16). Doğal gazın kimyasal özellikleri ve kullanım alanları. Retrieved from https://www.tesisat.org/dogal-gazin-kimyasal-ozelikleri-ve-kullanim-alanlari.html.
Balmer, R. (2011). Modern engineering thermodynamics. Academic Press.
Ozturk, A., Kılıç, A., & Yavuz, H. (2007). Thermodynamics and heat transfer tables (4th ed., 2nd printing).
Cengel, Y. A., Boles, M. A., & Kanoğlu, M. (2011). Thermodynamics: An engineering approach (Vol. 5, p. 445). McGraw-Hill.
Cengel, Y. A. (2006). Heat transfer: A practical approach (5th ed.). McGraw-Hill.
AZoM. (2022, February 7). Thermal conductivity coefficient of AISI 1010. Retrieved from https://www.azom.com/article.aspx?ArticleID=6539.
Izocam. (2022). Thermal conductivity coefficient of rockwool. Retrieved February 7, 2022, from https://www.izocam.com.tr/tr/urun-grubu/tasyunu
AZoM. (2022). Thermal conductivity coefficient of AISI 430. Retrieved February 7, 2022, from https://www.azom.com/properties.aspx?ArticleID=996
Incropera, F. P. (2007). Fundamentals of heat and mass transfer (6th ed.). John Wiley & Sons.
Hepbasli, A. (2008). A key review on exergetic analysis and assessment of renewable energy resources for a sustainable future. Renewable and Sustainable Energy Reviews, 12(3), 593-661. https://doi.org/10.1016/j.rser.2006.10.001
Caliskan, H., & Hepbasli, A. (2010). Energy and exergy prices of various energy sources along with their CO2 equivalents. Energy Policy, 38(7), 3468-3481. https://doi.org/10.1016/j.enpol.2010.02.020
Moran, M. J., Shapiro, H. N., Boettner, D. D., & Bailey, M. B. (2014). Fundamentals of engineering thermodynamics (8th ed.). Wiley.
Ozdemir, E., & Kılıç, M. (2018). Thermodynamic analysis of basic and regenerative organic Rankine cycles using dry fluids from waste heat recovery. Journal of Thermal Engineering, 4(5), 2381-2393.
Choi, Y. O. M. R. (1986). Effects of temperature and composition on the thermal properties of foods. Transport Phenomena, 99-101.