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Journal of Thermal Analysis and Calorimetry

, Volume 133, Issue 2, pp 1001–1013 | Cite as

Energy- and exergy-based thermal analyses of a solar bakery unit

  • Iqra Ayub
  • Anjum Munir
  • Waseem Amjad
  • Abdul Ghafoor
  • Muhammad Salman Nasir
Article

Abstract

The use of solar concentrating technique for cooking purpose has been widely reported rather than for the baking process which is rigidly precise and requires process controlled conditions. Secondly, the energy and exergy analyses are rarely made for the baking process. In this paper, an energy- and exergy-based thermal analysis of an innovative solar bakery unit powered by Scheffler reflector has been presented. The system comprised of primary reflector (Scheffler reflector), secondary reflector, receiver and baking chamber. The baking experiments were conducted using four product samples (cakes) at 180 °C. The entire bakery unit was divided into two main parts, i.e. fan–receiver and baking chamber to find out the inefficiencies of bakery unit and its components. It was found that fan–receiver component handled major portion of solar energy and showed energy losses. It possessed high improvement potential (IP) rate (0.153 kW), high exergetic factor (f) value (59.26%) and low exergy efficiency (15%). Thermal analysis of baking process in the baking chamber showed variations in rate of energy utilization, energy utilization ratio, exergy losses and exergy efficiency in range of 0.01–0.07 kW, 25–75%, 0.19–1.08 kW and 6.62–56.46%, respectively. The overall exergy efficiency of system was found to be 59.26%. The study provides a detailed and sequential procedure to perform the thermal analysis of a solar concentrated technology-based bakery unit.

Keywords

Solar baking Thermal analysis Scheffler reflector Exergy 

List of symbols

W

Rate of energy utilization/kJ s−1

Qnet

Net available energy/kJ s−1

T

Temperature/°C

ηr

Receiver efficiency/%

ma

Air flow rate/kg s−1

ω

Specific humidity/g of water kg of dry air−1

h

Enthalpy/kJ kg−1

ϕ

Relative humidity/%

v

Air velocity/m s−1

Cp

Specific heat/kJ kg−1 k−1

Qd

Heat given by receiver to air as output/kW

QR

Heat received by zigzag receiver/kW

Ib

Beam radiations/W m−2

Ap

Aperture area of Scheffler reflector/m2

Ac

Surface area of Scheffler reflector/m2

δ

Solar declination

EUR

Energy utilization ratio/%

Ex

Exergy/kJ kg−1

Exr

Exergy rate/kJ s−1

ηEX

Exergetic efficiency/%

f

Exergetic factor/%

IP

Improvement potential/kJ s−1

Notes

Acknowledgements

The authors wish to acknowledge the Department of Energy Systems Engineering, University of Agriculture Faisalabad, Pakistan, and International Centre for Development and Decent Work (ICDD), Germany, for the financial support.

References

  1. 1.
    Pohekar SD, Kumar D, Ramachandran M. Dissemination of cooking energy alternatives in India—a review. Renew Sustain Energy. 2005;9:379–93.CrossRefGoogle Scholar
  2. 2.
    Esen M. Thermal performance of a solar cooker integrated vacuum-tube collector with heat pipes containing different refrigerants. Sol Energy. 2004;76:751–7.CrossRefGoogle Scholar
  3. 3.
    Terres H, Ortega JA, Gordon M, Morales JR, Lizard A. Heating of bee honey, olive oil, milk and water in a solar box type with internal reflectors. In: Energy sustainability conference, Long Beach, California, USA; 27–30 June 2007.Google Scholar
  4. 4.
    Hussein HMS, El-Ghetany HH, Nada SA. Experimental investigation of novel indirect solar cooker with indoor PCM thermal storage and cooking unit. Energy Convers Manag. 2008;49:2237–46.CrossRefGoogle Scholar
  5. 5.
    Meibodi SS, Kianifar A, Mahian O, Wongwises S. Second law analysis of a nano-fluid-based solar collector using experimental data. J Therm Anal Calorim. 2016;126:617–26.CrossRefGoogle Scholar
  6. 6.
    Kumar RA, Babu BG, Mohanraj M. Thermodynamic performance of forced convection solar air heaters using pin–fin absorber plate packed with latent heat storage materials. J Therm Anal Calorim. 2016;126:1657–78.CrossRefGoogle Scholar
  7. 7.
    Farooqui SZ. A review of vacuum tube based solar cookers with the experimental determination of energy and exergy efficiencies of a single vacuum tube based prototype. Renew Sustain Energy Rev. 2014;31:439–45.CrossRefGoogle Scholar
  8. 8.
    Rabha DK, Muthukumar P, Somayaji C. Energy and exergy analyses of the solar drying processes of ghost chilli pepper and ginger. Renew Energy. 2017;105:764–73.CrossRefGoogle Scholar
  9. 9.
    Sogut Z, Ilten N, Oktay Z. Energetic and exergetic performance evaluation of the quadruple-effect evaporator unit in tomato paste production. Energy. 2010.  https://doi.org/10.1016/j.energy.2010.05.035.Google Scholar
  10. 10.
    Nahar NM. Performance and testing of an improved hot box solar cooker. Energy Convers Manag. 1990;30:9–16.CrossRefGoogle Scholar
  11. 11.
    Nahar M. Studies on a hot box solar cooker with transparent insulation material. Energy Convers Manag. 1994;9:787–91.CrossRefGoogle Scholar
  12. 12.
    Algifri H, Al-Towaie HA. Efficient orientation impacts of box-type solar cooker on the cooker performance. Sol Energy. 2001;70:165–70.CrossRefGoogle Scholar
  13. 13.
    Nouni MR, Mullick SC, Kandpal TC. An energy analysis of box-type solar cooker utilization in India. Int J Ambient Energy. 2008;29(1):45–56.CrossRefGoogle Scholar
  14. 14.
    Sharma SD, Iwata T, Kitano H, Sagara K. Thermal performance of a solar cooker based on an evacuated tube solar collector with a PCM storage unit. Sol Energy. 2005;78:416–26.CrossRefGoogle Scholar
  15. 15.
    Singh H, Saini K, Yadav A. Experimental investigation of the solar cooker during sunshine and off-sunshine hours using the thermal energy storage unit based on a parabolic trough collector. Int J Ambient Energy. 2016.  https://doi.org/10.1080/01430750.2015.1023836.Google Scholar
  16. 16.
    Stumpf P, Balzar A, Eisenmann W, Wendt S, Ackermann H, Vagen K. Comparative measurements and theoretical modelling of single-and double-stage heat pipe coupled solar cooking systems for high temperatures. Sol Energy. 2001;71(1):1–10.CrossRefGoogle Scholar
  17. 17.
    Kumar R, Adhikari RS, Garg HP, Kumar A. Thermal performance of a pressure cooker based on evacuated tube solar collector. Appl Therm Eng. 2001;21:1699–706.CrossRefGoogle Scholar
  18. 18.
    Harmim A. Experimental investigation of a box-type solar cooker with a finned absorber plate. Energy. 2010;35(3):799–802.Google Scholar
  19. 19.
    Richard P. Exergy analysis of the solar cylindrical-parabolic cooker. Sol Energy. 2005;79:221–33.CrossRefGoogle Scholar
  20. 20.
    Shukla SK, Gupta SK. Performance evaluation of concentrating solar cooker under Indian climatic conditions. In: Second international conference on energy sustainability, Jacksonville, Florida, USA; 10–14 August 2008.Google Scholar
  21. 21.
    Panwar NL, Kaushik SC, Surendra K. Experimental investigation of energy and exergy efficiencies of domestic size parabolic dish solar cooker. J Renew Sustain Energy. 2012.  https://doi.org/10.1063/1.3699615.Google Scholar
  22. 22.
    Pandey AK, Tyagi VV, Park SR, Tyagi SK. Comparative experimental study of solar cookers using exergy analysis. J Therm Anal Calorim. 2012;109:425–31.CrossRefGoogle Scholar
  23. 23.
    Park SR, Pandey AK, Tyagi VV, Tyagi SK. Energy and exergy analysis of typical renewable energy systems. Renew Sustain Energy Rev. 2014;30:105–23.CrossRefGoogle Scholar
  24. 24.
    Zamani H, Mahian O, Rashidi I, Lorenzini G, Wongwises S. Exergy optimization of a double exposure solar cooker by response surface method. J Therm Sci Eng Appl. 2017;9:011003-1.  https://doi.org/10.1115/1.4034340.Google Scholar
  25. 25.
    Mbodji N, Hajji A. Modelling, testing and parametric analysis of a parabolic solar cooking system with heat storage for indoor cooking. J Energy Sustain Soc. 2017;7:32.  https://doi.org/10.1186/s13705-017-0134-z.CrossRefGoogle Scholar
  26. 26.
    Hassen A, Kebedy SB, Wihib NM. Design and manufacturing of thermal energy based Injeria baking glass pan. Energy Procedia. 2016;93:153–9.CrossRefGoogle Scholar
  27. 27.
    Tesfay AH, Kahsay MB, Nadal OJ. Design and development of solar thermal injeria baking; steam based direct baking. Energy Procedia. 2013;57:2946–55.CrossRefGoogle Scholar
  28. 28.
    Sansaniwal SK, Sharma V, Mathur J. Energy and exergy analyses of various typical solar energy applications: a comprehensive review. J Sustain Energy Rev. 2017.  https://doi.org/10.1016/j.rser.2017.07.003.Google Scholar
  29. 29.
    Schirmer P, Janjai S, Esper A, Smitabhindu R, Muhlbaur W. Experimental investigation of the performance of the solar tunnel dryer for drying Bananas. Renew Energy. 1996;7:119–29.CrossRefGoogle Scholar
  30. 30.
    Midilli A, Kucuk H. Energy and exergy analyses of solar drying process of pistachio. Energy. 2003;28:539–56.CrossRefGoogle Scholar
  31. 31.
    Mujumdar AS. Hand book of industrial drawing. 2nd ed. New York: Marcel Dekker; 1995.Google Scholar
  32. 32.
    Amjad W, Hensel O, Munir A, Esper A, Sturm B. Thermodynamic analysis of drying process in a diagonal-batch dryer developed for batch uniformity using potato slices. J Food Eng. 2016;169:238–49.CrossRefGoogle Scholar
  33. 33.
    Holman JP. Experimental methods for engineers. 6th ed. Singapore: McGraw-Hill; 1994 (International ed.).Google Scholar
  34. 34.
    Erbay Z, Icier F. Energy and exergy analyses on drying of olive leaves (Olea europaea) in tray drier. J Food Process Eng. 2011;34(6):2105–23.CrossRefGoogle Scholar
  35. 35.
    Ozturk HH. Comparison of energy and exergy efficiency for solar box and parabolic cookers. J Energy Eng. 2007;133(1):53–62.CrossRefGoogle Scholar
  36. 36.
    Kumar N, Vishwanath G, Gupta A. An exergy based unified test protocol for solar cookers of different geometries. In: World Renewable Energy Congress 2011 Sweden, Solar Thermal Applications, 2011; p. 3741–8.Google Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2018

Authors and Affiliations

  • Iqra Ayub
    • 1
  • Anjum Munir
    • 1
  • Waseem Amjad
    • 1
  • Abdul Ghafoor
    • 2
  • Muhammad Salman Nasir
    • 3
  1. 1.Department of Energy Systems EngineeringUniversity of Agriculture FaisalabadFaisalabadPakistan
  2. 2.Department of Farm Machinery and PowerUniversity of Agriculture FaisalabadFaisalabadPakistan
  3. 3.Department of Structures and Environmental EngineeringUniversity of Agriculture FaisalabadFaisalabadPakistan

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