Document Type : Original Article

Authors

1 Ph.D. Candidate, Department of Biosystems Engineering, College of Aburaihan, University of Tehran

2 Associate Perofessor, College of Aburaihan, University of Tehran, Tehran, Iran

3 Associate Professor, Agricultural Engineering Research Institute (AERI), Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran

4 Professor, Department of Agricultural & Biological Engineering, Purdue University, West Lafayette, USA,

Abstract

Among renewable and clean energies, geothermal energy is superior to other types of energy, and unlike other renewable energies, it is not limited to the season, time, and conditions. One of the applications of geothermal energy is the use of ground heat at shallow depths as the earth-air heat exchanger (EAHE), which is used as a modern and effective technique for preheating the air in the winter and vice versa precooling in the summer. In this study, the design of an EAHE converter for a commercial greenhouse for heating or cooling purposes was examined. A one-dimensional model of the EAHE system was developed to evaluate the effects of main parameters such as diameter, length, air flow rate, and fan power and system efficiency. Given the direct relationship between number of the transfer units (NTU) and the effictiveness of EAHE (ε), it is possible to construct an EAHE system in order to obtain an appropriate NTU and its ε and handle the design of an EAHE system to a point where these two parameters will be obtained with the desired values. By the model and method presented in this study, the effects of main parameters as the effective design factors can be simply assessed without any waste of energy and time and complexity.

Keywords

Anon. (2012). Handbook heating, ventilating, and air-conditioning system and equipement. ASHRAE, Atlanta, GA The American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc.
 
Anon. (2016).  Paris agreement, United Nations Treaty Collection.
 
Ascione, F., Bellia, L., & Minichiello, F. (2011). Earth-to-air heat exchangers for Italian climates. Renewable Energy, 36, 2177- 2188.
 
Badescu, V., & Isvoranu, D. (2011). Pneumatic and thermal design procedure and analysis of earth-to-air heat exchangers of registry type. Applied Energy, 88(4), 1266-1280.
 
Bisoniya, T. S. (2015). Design of earth–air heat exchanger system. Geothermal Energy, 3(18), 1-10.
 
Cengel, Y. A., Afshin, J. Gh., & Hsiaokang, M. (2011). Heat and mass transfer: fundamentals & applications. 4e. McGraw-Hill.
 
De Paepe, M., & Janssens, A. (2003). Thermo-hydraulic design of earth-air heat exchangers. Energy Buildings35(4), 389-397.
 
Ghosal, M. K., & Tiwari, G. N. (2006). Modeling and parametric studies for thermal performance of an earth to air heat exchanger integrated with a greenhouse. Energy Conversion and Management, 47(13-14), 1779-1798.
 
Gouda, S. G. A. (2010). Using of geothermal energy in heating and cooling of agricultural structures (Ph. D. Thesis), BENHA University.
 
Kanaris, A. G., Mouza, A. A., & Paras, S. V. (2006). Flow and heat transfer prediction in a corrugated plate heat exchanger using a CFD code. Chemical Engineering and Technology: Industrial ChemistryPlant EquipmentProcess EngineeringBiotechnology29(8), 923-930.
 
Lindeburg, M. R. (1992). Engineer in training reference manual. Professional Publication, Inc. 8th Edition.
 
Luciu, R. S., Mateescu, T., Cotorobai, V., & Mare, T. (2009). Nusselt number and convection heat transfer coefficient for a coaxial heat exchanger using Al2O3–water pH= 5 nanofluid. The Bulletin of the Polytechnic Institute of Jassy, 55, 71-80.
 
Mikani, A., Etebarian, H. R., Sholberg, P. L., O’Gorman, D. T., Stokes, S., & Alizadeh, A. (2008). Biological control of apple gray mold caused by Botrytis Mali with Pseudomonas fluorescens strains. Postharvest Biology and Technology, 48(1), 107-112.
 
Mongkon, S., Thepa, S., Namprakai, P., & Pratinthong, N. (2014). Cooling performance assessment of horizontal earth tube system and effect on planting in tropical greenhouse. Energy Conversion and Management, 78, 225-236.
 
Nakamura, H., & Igarashi, T. (2004). Variation of Nusselt number with flow regimes behind a circular cylinder for Reynolds numbers from 70 to 30 000. International Journal of  Heat and Mass Transf.er, 47(23), 5169-5173.
 
Sehli, A., Hasni, A., & Tamali, M. (2012). The potential of earth-air heat exchangers for low energy cooling of buildings in South Algeria. Energy Procedia, 18, 496-506.
 
Sethi, V. P., & Sharma, S. K. (2008). Survey and evaluation of heating technologies for worldwide agricultural greenhouse applications. Solar Energy. 82(9), 832-859.
 
T’Joen, C., Liu, L., & Paepe, M. D. (2012). Comparison of Earth-Air and Earth-Water Ground Tube Heat Exchangers for Residentialal Application. 14th International Refrigeration and Air-Conditioning Conference, July 16-19. Purdue University, West Lafayette, United States.
 
Vourdoubas, J. (2004). Comparison of greenhouse heating with geothermal energy, solar energy and biomass. International Conference Geothermal Energy Applications in Agriculture. May 3-4, Athens, Greece.
 
Vourdoubas, J. (2015). Overview of heating greenhouses with renewable energy sources a case study in Crete-Greece. Journal of Agriculture and Environmental Science, 4(1), 70-76.
 
Wang, Y., Dong, Q., & Liu, M. (2007). Characteristics of Fluid flow and heat transfer in shellside of heat exchangers with longitudinal flow of shellside fluid with different supporting structures. In: C. Cen,, Chi, Y., & Wang, F. (Eds.) Challenges of power engineering and environment. Springer, Berlin, Heidelberg.
 
Xiao, B., Wang, G., Wang, Q., Maniruzzaman, M., Sisson, R. D., & Rong, Y. (2011). An experimental study of heat transfer during forced air convection. Journal of Materials Engineering and Performance, 20(7), 1264-1270.
 
Yener, D., Ozgener, O., & Ozgener, L. (2017). Prediction of soil temperatures for shallow geothermal applications in Turkey. Renewable and Sustainable Energ Reviews, 70, 71-77.