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Improving Solar Dryers’ Performances Using Design and Thermal Heat Storage

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Abstract

Solar drying is one of the most important processes used by the farmers and the agriculture producers especially in developing countries, at the same time as using free solar energy permits to reduce the cost of the operation. However, in order to face or to limit the intermittent character of solar energy, storage is proposed as a solution. It is found that two ways are used for the thermal energy storage: thermal and chemical ways. Nevertheless, thermal way is the most useful for solar drying. We present, in this paper, a classification of the common methods of thermal energy storage applied to solar drying with the presentation of the optimum design parameters for the studied dryers. It was found that the most frequent materials used for energy storage during solar drying are packed-bed storage with the use of rocks, sands, or gravels. The packed bed can be added to the drying chamber, to the solar collector, or both of them. Also, desiccants, such as a mixture of several chemical products or wheat, can find applications as storage material used for solar drying process. Water is the other proposed storage material; it is used according to its availability, cost, and some of its thermo-physical characteristics. Latent heat storage has found a little application for solar drying. In general manner and depending on the dried product, the insert of the thermal energy storage increases the efficiencies of the solar dryers and allows recovering the surplus of solar radiations during sunshine periods for a reuse during the off-sunshine periods. The study is ended by an economic analysis of some developed solar dryers.

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Abbreviations

A :

Surface (m2)

C or Cp:

Specific heat capacity (J kg−1 °C−1)

D :

Diameter (m)

G :

Air mass velocity through grain bed/rock bed (kg s−1 m−2)

g :

Gravitational acceleration (m s−2)

H :

Height (m)

h or h c :

Convective heat transfer coefficient (W m−2 °C−1)

h as :

Adiabatic saturation humidity of air entering the drying chamber (kg water kg−1 dry air)

h i :

Absolute humidity of air entering the drying chamber (kg water kg−1 dry air)

I :

Hourly average solar radiation on inclined surface (W m−2)

L c or L g :

Latent heat of vaporisation (J kg−1)

M or m :

Mass (kg)

Mev:

Hourly moisture evaporation (kg h−1)

mw :

Moisture evaporated in time (kg s−1)

m a or \(\dot{m}_{a}\) :

Mass flow rate (kg s−1)

P d :

Blower power (J)

Q f :

Amount of heat energy consumed by the fan (J)

Q h :

Amount of heat energy given by the heater (J)

Q p :

Amount of heat energy consumed by the pump (J)

T :

Temperature (°C)

T fHS :

Final temperature of heat storage material (°C)

T iHS :

Initial temperature of heat storage material (°C)

T i :

Inlet air temperature (°C)

T :

Time (s)

U L :

Overall heat loss coefficient from chimney (W m−2 °C−1)

W :

Air humidity (kg kg−1)

X :

Dimension (m)

Z :

Height above drying bed (m)

ΔP :

Pressure drop (N m−2)

ΔT :

Difference between ambient and component air temperature (°C)

β:

Coefficient of thermal expansion (°C−1)

ε:

Porosity or emissivity

η:

Thermal efficiency

ρ:

Density (kg/m3)

a:

Air or ambient

b:

Packed bed

c:

Crop or collector

ch:

Chamber

d:

Day

E0 :

Inlet exchange-storage unit

E1 :

Outlet exchange-storage unit

f:

Fluid in grain

g:

Global

i:

Number of side wall of dryer or the number of reflector or inlet

n:

Night

o:

Outlet

R:

Rock

p:

Absorber plate or pickup

RB:

Rock bed

s:

Storage material

t:

Time

th:

Thermal

w:

Water

0:

Initial

References

  1. Abhat A (1983) Low-temperature latent heat thermal energy storage: heat storage material. Sol Energy 30:313–332

    Article  CAS  Google Scholar 

  2. Amer BMA, Hossain MA, Gottschalk K (2010) Design and performance evaluation of a new hybrid solar dryer for banana. Energ Convers Manage 51:813–820

    Article  Google Scholar 

  3. Aregba AW, Nadeau JP (2007) Comparison of two non-equilibrium models for static grain deep-bed drying by numerical simulations. J Food Eng 78:1174–1187

    Article  Google Scholar 

  4. Aregba AW, Sebastian P, Nadeau JP (2007) Stationary deep-bed drying: a comparison study between logarithmic model and a non-equilibrium model. J Food Eng 77:27–40

    Article  Google Scholar 

  5. Arnaud G, Fohr JP (1998) Slow drying simulation in thick layers of granular products. Int J Heat Mass Tran 31:2517–2526

    Article  Google Scholar 

  6. Ayensu A, Asiedu-Bondzie V (1986) Solar drying with convective self-flow and energy storage. Sol Wind Technol 4:273–279

    Article  Google Scholar 

  7. Bal LM, Sudhakar P, Satya S, Naik SN (2009) Solar dryer with latent heat storage systems for drying agricultural food products. In: Proceedings of the International Conference on Food Security and Environmental Sustainability

  8. Bal LM, Satya S, Naik SN (2010) Solar dryer with thermal energy storage systems for drying agricultural food products: a review. Renew Sust Energ Rev 14:2298–2314

    Article  Google Scholar 

  9. Bal LM, Satya S, Naik SN, Meda V (2011) Review of solar dryers with latent heat storage systems of agricultural products. Renew Sust Energ Rev 15:876–880

    Article  Google Scholar 

  10. Bala BK, Woods JL (1994) Simulation of the indirect natural convection solar drying of rice. Sol Energy 53:259–266

    Article  Google Scholar 

  11. Bala BK, Woods JL (1995) Optimisation of natural-convection, solar drying systems. Energy 20:285–294

    Article  Google Scholar 

  12. Bennamoun L (2011) Reviewing the experience of solar drying in Algeria with presentation of the different design aspects of solar dryers. Renew Sust Energ Rev 15:3371–3379

    Article  Google Scholar 

  13. Bennamoun L, Belhamri A (2003) Design and simulation of a solar dryer for agriculture products. J Food Eng 59:259–266

    Article  Google Scholar 

  14. Bennamoun L, Belhamri A (2008) Mathematical description of heat and mass transfer during deep bed drying: effect of product shrinkage on bed porosity. Appl Therm Eng 28:2236–2244

    Article  CAS  Google Scholar 

  15. Bennamoun L, Belhamri A (2008) Study of heat and mass transfer in porous media: application to packed-bed drying. Fluid Dyn Mater Process 4:221–230

    Google Scholar 

  16. Bennamoun L, Belhamri A (2011) Study of solar thermal energy in the north region of Algeria with simulation and modeling of an indirect convective solar drying system. Nature & Technol 4:34–40

    Google Scholar 

  17. Boughali S, Benmoussa H, Bouchekima B, Mennouche D, Bouguettaia H, Bechki D (2009) Crop drying by indirect active hybrid solar-electrical dryer in the eastern Algerian Septentrional Sahara. Sol Energy 83:2223–2232

    Article  Google Scholar 

  18. Chauhan PM, Choudhury C, Garg HP (1996) Comparative performance of coriander dryer coupled to solar air heater and solar air-heater-cum-rockbed storage. Appl Therm Eng 16:475–486

    Article  Google Scholar 

  19. Daguenet M (1985) Les séchoirs solaires: théorie et pratique. UNESCO, Paris

    Google Scholar 

  20. Devahastin S, Pitaksuriyarat S (2006) Use of latent heat storage to converse energy during drying and its effect on drying kinetics of a food product. Appl Therm Eng 26:1705–1713

    Article  Google Scholar 

  21. Duffie JA, Beckman WA (1991) Solar engineering of thermal processes. Wiley, New York

    Google Scholar 

  22. Ekechukwu OV, Norton B (1999) Review of solar-energy drying systems II: an overview of solar drying technology. Energ Convers Manage 40:615–655

    Article  CAS  Google Scholar 

  23. El-Sebaii AA, Abou-Enein S, Ramadan MRI, El Gohary HG (2002) Empirical correlations for drying kinetics of some fruits and vegetables. Energy 27:845–859

    Article  Google Scholar 

  24. Esen M, Durmus A (1998) Geometric design of solar aided latent heat storage depending on various parameters and phase change materials. Sol Energy 62:19–28

    Article  CAS  Google Scholar 

  25. Fudholi A, Sopian K, Ruslan MH, Alghoul MA, Sulaiman MY (2010) Review of solar dryers for agricultural and marine products. Renew Sust Energ Rev 14:1–30

    Article  Google Scholar 

  26. Gong ZX, Mujumdar AS (1996) Enhancement of energy charge-discharge rates in composite slabs of different phase change materials. Int J Heat Mass Tran 39:725–733

    Article  CAS  Google Scholar 

  27. Gong ZX, Mujumdar AS (1996) Cycle heat transfer in a novel storage unit of multiple phase change materials. Appl Therm Eng 16:807–815

    Article  CAS  Google Scholar 

  28. Gong ZX, Mujumdar AS (1997) Finite-element analysis of cyclic heat transfer in a shell-and-tube latent heat energy storage exchanger. Appl Therm Eng 17:583–591

    Article  CAS  Google Scholar 

  29. Hassan M, Mujumdar AS, Weber ME (1991) Cyclic melting and freezing. Chem Eng Sci 46:1573–1587

    Article  Google Scholar 

  30. Hossain MA, Woods JL, Bala BK (2005) Optimisation of solar tunnel drier for drying of chilli without color loss. Renew Energy 30:729–742

    Article  Google Scholar 

  31. Hsu CT (2000) Heat conduction in porous media. In: Vafai K (ed) Handbook of porous media. Marcel Dekker, New York

    Google Scholar 

  32. Imre L (2006) In: Mujumdar AS (ed) Solar drying, Handbook of industrial drying, CRC Press; 2006 [chapter 13]

  33. Jain D (2005) Modeling the system performance of multi-tray crop drying using an inclined multi-pass solar air heater with in built thermal storage. J Food Eng 71:44–54

    Article  Google Scholar 

  34. Jain D (2007) Modeling the performance of the reversed absorber with packed bed thermal storage natural convection solar crop dryer. J Food Eng 78:637–647

    Article  Google Scholar 

  35. Jain D, Jain K (2004) Performance evaluation of an inclined multi-pass solar air heater with in-built thermal storage on deep-bed drying application. J Food Eng 65:497–509

    Article  Google Scholar 

  36. Jariwala VG, Mujumdar AS, Weber ME (1987) Periodic steady state for cyclic energy storage in paraffin wax. Can J Chem Eng 65:899–906

    Article  CAS  Google Scholar 

  37. Lacroix M (1993) Study of the heat transfer behavior of a latent heat thermal energy storage unit with a finned tube. Int J Heat Mass Tran 36:2083–2092

    Article  CAS  Google Scholar 

  38. Luna D, Nadeau JP, Jannot Y (2010) Model and simulation of a solar kiln with energy storage. Renew Energ 35:2533–2542

    Article  Google Scholar 

  39. Madhlopa A, Ngwalo G (2007) Solar dryer with thermal storage and biomass-backup heater. Sol Energy 81:449–462

    Article  Google Scholar 

  40. Mohanraj M, Chandrasekar P (2009) Performance of the forced convection solar drier integrated with gravel as heat storage material for chili drying. J Eng Sci Technol 4:305–314

    Google Scholar 

  41. Mumba J (1995) Economic analysis of a photovoltaic, forced convection, solar grain dryer. Energy 20:923–928

    Article  Google Scholar 

  42. Mumba J (1996) Design and development of a solar grain dryer incorporating photovoltaic powered air circulation. Energ Convers Manage 37:615–621

    Article  Google Scholar 

  43. Nield DA, Bejan A (2006) Convection in porous media. Springer, New York

    Google Scholar 

  44. Puiggali JR, Penot F (1983) Analyse du comportement dynamique et thermique d’un séchoir solaire constitué d’un capteur à matrice poreuse couplé à une cheminée solaire. Rev Phy Appl 18:625–633

    Article  Google Scholar 

  45. Puurohit P, Kandpal TC (2005) Solar crop dryer for saving commercial fuels: a techno-economic evaluation. Inter J Ambient Energy 26:3–12

    Article  Google Scholar 

  46. Quintard M, Whitaker S (2000) Theoretical analysis of transport in porous media. In: Vafai K (ed) Handbook of porous media. Marcel Dekker, New York

    Google Scholar 

  47. Rathore NS, Panwar NL (2011) Design and development of energy efficient solar tunnel dryer for industrial drying. Clean Techn Environ policy 13:125–132

    Article  CAS  Google Scholar 

  48. Shanmugam V, Natarajan E (2006) Experimental investigation of forced convection and desiccant integrated solar dryer. Renew Energ 31:1239–1251

    Article  CAS  Google Scholar 

  49. Sharma SD, Buddhi D, Sawhney RL (1999) Accelerated thermal cycle test of latent heat-storage materials. Sol Energy 66:483–490

    Article  CAS  Google Scholar 

  50. Sharma A, Tyagi VV, Chen CR, Buddhi D (2009) Review on thermal energy storage with phase change materials and applications. Renew Sust Energ Rev 13:318–345

    Article  CAS  Google Scholar 

  51. Singh PL (2011) Silk cocoon drying in forced convection type solar dryer. Appl Energy 88:1720–1726

    Article  Google Scholar 

  52. Sreekumar A (2010) Techno-economic analysis of a roof-integrated solar air heating system for drying fruit and vegetables. Energ Convers Manage 51:2230–2238

    Article  Google Scholar 

  53. Sreekumar A, Manikatan PE, Vijayakumar KP (2008) Performance of indirect solar cabinet dryer. Energ Convers Mange 49:1388–1395

    Article  CAS  Google Scholar 

  54. Thoruwa TFN, Johnstone CM, Grant AD, Smith JE (2000) Novel low cost CaCl2 based desiccants for solar crop drying applications. Renew Energ 19:513–520

    Article  CAS  Google Scholar 

  55. Whitaker S (1980) In: Mujumdar AS (ed) Heat and mass transfer in granular porous media, Advances in drying I. Hemisphere Publication, New York

    Google Scholar 

  56. Ziegler T, Richter IG, Pecenka R (1999) Desiccant grain applied to the storage of solar drying potential. Drying Technol 17:1411–1427

    Article  Google Scholar 

Download references

Acknowledgments

The author is grateful to the Belgian National Fund of Scientific Research (F.R.S.-F.N.R.S.) for his short-term Foreign Postdoctoral Fellow position.

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  1. Department of Mechanical Engineering, University of New Brunswick, 15 Dineen Drive, E3B 5A3, Fredericton, New Brunswick, Canada

    Lyes Bennamoun

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Bennamoun, L. Improving Solar Dryers’ Performances Using Design and Thermal Heat Storage. Food Eng Rev 5, 230–248 (2013). https://doi.org/10.1007/s12393-013-9073-4

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